The Segway Is A Vehicle

[bicycledriver]

Article: "The Segway Is A Vehicle" posted at www.humantransport.org

Excerpt:
"So far Segway LLC has been highly successful in its lobbying for state traffic regulations that treat the Segway as a pedestrian tool, despite the objections of pedestrians. Although this outcome may be good for short-term sales of Segways, it is not at all clear that this regulation is in the best interest of the future Segway drivers themselves. If the Segway is improperly regulated, the regulations could generate serious hazards, inconveniences and barriers to those who travel by Segway. This article examines the problems that may be created for Segway drivers and other road users if these vehicles are regulated by pedestrian rules, and suggests an alternative approach."

See the rest at
http://www.humantransport.org/bicycledriving/library/segway/Segway.htm

[ftropea]

Haven't read it all yet, but I already have a question about this part:

"A critical difference between pedestrians and vehicles is stopping distance. Most pedestrians can come to a complete stop in one or two steps, while vehicles require greater time and distance to stop from their typical free-flow travel speeds. Segway LLC has not published stopping distance data for the Segway operated at cruising speed; this metric must therefore be estimated from the physical laws of motion. (One must question why Segway LLC has not released stopping distance figures since surely this parameter must be known by its developers.) The simple equation for braking distance d to arrive at a stop, assuming a constant rate of deceleration,"

What speeds were those pedestrians traveling at? I assume walking speed and not more than 3mph. If comparing stopping distance between a pedestrian and a Segway-HT, wouldn't it be a more accurate to compare them at equal speeds?

How about a person running... measure the stopping distance.

Same holds true for bikes...

And then a person on a Segway-HT...

I recently tried out a Segway-HT for a few hours and estimated my stopping distance was anywhere from 2 - 3 feet when coming to a complete stop from full speed... around 10 - 12mph. Can't be absolutely sure about that because I didn't have a measuring tape handy.

Thanks and welcome to the forum! I can't wait to read the entire analysis. Looks interesting... :)

Regards,

Frank A. Tropea

[JohnM]

Welcome aboard BD. Excellent article. Too bad no one else here will be bothered to read it. Well, maybe Frank. ;)

quote:
The first priority of Segway legislation should be to do no harm. Responsible traffic laws are carefully crafted such that they never require a driver to operate more dangerously than an alternative method. In the case of the Segway, it is likely that following the rules that apply to drivers of vehicles will be safer than following the rules for pedestrians in most situations. Segway laws should therefore allow Segway operators to travel according to vehicular rules and prohibit Segway drivers from doing things that have been demonstrated to be especially hazardous. However, there may be situations (such as with properly trained service workers) where it may be advantageous and reasonably safe to allow Segway operation on pedestrian facilities if Segway operators can be educated and enforced to travel at slow pedestrian speeds and to use great care.

The true Segway fan holds two beliefs that will make the author's conclusions appear irrelevent to them.
1. The Segway is 100% safe. There are no hazards to operating a Segway.
2. The Segway is 100% unique. Drawing comparisons between Segway and any other vehicle or device are meaningless.

In the eyes of most posters in this forum, to believe otherwise is heresy. But I can't hold that against them. Even among bike riders it is hard to gain acceptance of Forester's concepts of vehicular cycling. Vehicular Segwaying will be a hard sell.





Runnin' with the Big Dogs

[bicycledriver]

Frank,

Thanks for your question. The paper discusses the dynamics of braking and the stopping distance for a useful cruising speed. The paper is more concerned with the top cruising speed of the Segway than its performance at pedestrian speed because people use vehicles primarily to go faster than pedestrian speed. If the Segway's average speed is significantly less than an electric bicycle's, then people will use electric bicycles instead. Note that a pedestrian would quickly become exhausted traveling at such speeds, which is why pedestrians rarely run for utilitarian purposes (unless they are escaping from something!). The Segway user, however, has the benefit of motor power and will thus travel at the maximum speed whenever possible.

Steven Goodridge

[bicycledriver]

JohnM,

Thanks for your comments. I agree that "vehicular Segwaying" will be a tough sell in a nation where many uninformed cyclists don't behave like drivers of vehicles as the law provides. The main point of the article, however, is that while the existing traffic laws *allow* cyclists to act as drivers, and *prohibit* cyclists from doing those things that are known to be most unsafe for bicyclists, the Segway legislation does the opposite. Instead of simply *allowing* Segway drivers to operate by pedestrian rules under certian circumstances, the legislation promoted by Segway LLC here in North Carolina *mandates* that they operate that way, and deprives them of the rights of drivers of vehicles. This is really, really bad for Segway drivers compared to the conditions faced by cyclists.

Steve Goodridge
Member, Tau Beta Pi engineering honor society

[ftropea]

The Segway can also be used at pedestrian speed..

What would be the point?

It has the ability to carry a load in addition to the passenger.. makes it easier to transport goods, for example.

The only reason I asked about the breaking comparison was because I couldn't see comparing the braking distance of a pedestrian at walking speed with anything else at a greater speed... Segway or Bike. Of course it would be preferred to operate the Segway at speeds exceeding walking speeds... but perhaps doing that kind of breaking comparison really just becomes apples and oranges.

Regards,

Frank A. Tropea

[ftropea]

BD,

The Consumer Product Safety Commission (CPSC) and
the National Highway Traffic Safety Administration (NHTSA) have both classified the Segway-HT as a "consumer product" and not a "motor vehicle." Have you brought that study to their attention?

Regards,

Frank A. Tropea

[ftropea]

JohnM wrote:

"1. The Segway is 100% safe. There are no hazards to operating a Segway.
2. The Segway is 100% unique. Drawing comparisons between Segway and any other vehicle or device are meaningless."

John,

I'm a "true Segway fan" and I don't believe either is true. As to #1, everything is dangerous if you're irresponsible. And to #2, I don't believe the Segway is 100% unique, however I do believe it is different enough from bikes and that direct comparison shouldn't be made between the two.

If bikes could be safely operated on the sidewalks, I would be for that. However, they have been around for a lot longer than Segways and here in New York, for example, they're restricted to the streets and bike lanes. I think Segways should get their chance. The early adopters will decide Segway's fate. Will they rule the sidewalks or segue to the streets... time will tell.

BTW JohnM, I got to ride a Segway-HT for a day... and as I've mentioned, I own and have ridden a bike. Do I now have enough authority to speak towards the issues of Segway safety and use yet? :)

Regards,

Frank A. Tropea

[Casey]

quote: The true Segway fan holds two beliefs that will make the author's conclusions appear irrelevent to them.
1. The Segway is 100% safe. There are no hazards to operating a Segway.
2. The Segway is 100% unique. Drawing comparisons between Segway and any other vehicle or device are meaningless.

You have just declared that I AM NOT a "true Segway fan".

1. I do not, as I believe is true of other pro Segway posters, consider Segway "100% safe".

2.I do find Segway ALMOST 100% unique. But I do feel it is fair and necessary to compare it to OTHER vehicles. Yes, I did say OTHER because contrary to what Segway LLC or anybody else says, I consider Segway to be a vehicle.

I think you are confused by the fact that I find it unfair to condemn Segway as a hazard when there is no evidence to support that accusation. There have been millions of people injured by operating a computers, ie Carpal Tunnel Syndrome as well as repetitive stress injuries to the shoulder and neck muscles from prolonged use of a computer and keyboard. Yet I find nobody demanding that all computers be banned from libraries until it can be proven that they are harmless to human health.

Thinking Segway should be held innocent until proven guilty is somewhat different from thinking it is perfect.

[n/a]

quote:The true Segway fan holds two beliefs that will make the author's conclusions appear irrelevent to them.
1. The Segway is 100% safe. There are no hazards to operating a Segway.
2. The Segway is 100% unique. Drawing comparisons between Segway and any other vehicle or device are meaningless.


I want to give Segway the benefit of the doubt, but I dont consider myself to be a ture Segway fan because I dont subscribe to your criteria JohnM.

quote:...The Segway user, however, has the benefit of motor power and will thus travel at the maximum speed whenever possible.

The responsible Segway rider will travel at maximum speeds whenever possible considering the driving conditions. The irresponsible Segway driver may travel at maximum speeds whenever "physically" possible and take risks to themselves as well as to pedestrians. But since a Segway rider does risk injury to themselves when riding irresponsibly, it will motivate them to take into consideration when it is safe to drive at maximum speed.

[bicycledriver]

Sidewalk sight lines and surfaces are designed for typical pedestrian speeds (e.g. 2.5 mph) and stopping distances (e.g. 2-5 feet). Pedestrians and drivers typically assume these operational characteristics of sidewalk users. Traveling at greater speeds on sidewalks becomes progressively more risky to the sidewalk user, especially around driveways, intersections, and other sidewalk users.

If the Segway driver wishes to exploit the speed potential of his vehicle, he must either put himself (and others) at increased risk, or leave the sidewalk and operate as the driver of a vehicle on facilities designed for vehicles with maximum speeds and stopping distances greater than those of pedestrians.

Traffic laws that require Segway drivers to operate on pedestrian facilities or according to pedestrian rules elsewhere do harm to Segway operators by either requiring them to operate much slower than their vehicle's potential, or by makingthem face a higher risk of personal injury.

All of this has been understood for many years by competent bicycle drivers, and has been confirmed in studies of cyclist injuries. Cycling on sidewalks has been shown by numerous studies to yield a car-bike crash rate 2 to 4 times that of cycling on the adjacent roadway, and have an injury rate as high as 25 times that of roadway cycling, per mile of travel, even though sidewalk cycling is done at slower, less useful speeds than roadway cycling.

What is necessary for the safety and convenience of Segway drivers is for the Segway lobbyists and regulators to understand the laws of physics and the typical causes of crashes and injuries that apply users of light vehicles. My thesis is that if Segway use is to be popular inthe United States, these characteristics will be much more similar to US bicycle operation than the Segway proponents want to believe.

-Steve Goodridge

[n/a]

Steve, I want to state that this is by far the most serious piece of analysis I have seen thus far. It will take me a some time to absorb it all. But I will make some comments based on my impressions and look forward to your response.

quote: My thesis is that if Segway use is to be popular in the United States, these characteristics will be much more similar to US bicycle operation than the Segway proponents want to believe.


What Segway proponents "want to believe" may be a difficult issue to determine. How did u go about researching this? Can us show us your summary of what Segway proponents want to believe? As I understand it, Segway is still researching how to go about introducing the Segways to the public.

[JohnM]

Ok, ok, ok.
Just to keep the thread on track, I hereby retract, regret and apologize for saying the true Segway fans believe that: "The Segway is 100% safe. There are no hazards to operating a Segway". I was out of line.

But I think I can comfortably say that most true fans have a higher regard for Segway's safety performance than can be justified at this time with emperical evidence. Many will dispute Steve's 'Segway Maneuverability Limitations', basing their arguement on little more than Segway LLC's safety claims ('no mishaps') or their own limited riding experience. Who knows? Maybe they're right. But until Segway LLC can come up with something as simple as braking distances, I
appreciate Steve's analysis.

Runnin' with the Big Dogs

[ftropea]

JohnM,

Well.. limited Segway riding experience is probably better than none, so indulge me while I make the following point:

I didn't ride the Segway at more than 12.5mph... and the stopping distance wasn't more than 5 feet for sure. The study calculates that the "breaking distance" on a Segway at 15mph would be 12.5 feet? And that the "stopping distance" would be 34.5 feet?

Now, I admit I didn't travel at 15mph... but those number simply can't be true.

I went 12.5mph.. pulled and leaned back and stopped without losing my balance... and I stopped within a few feet. I didn't experience any uncomfortable forces either...

Believe it or not, it's true.

Weskifm.. you out there? Can you verify what I'm saying? Weskifm has over 50 hours of riding time...


Regards,

Frank A. Tropea

[bicycledriver]

Lawrence,

From reading the marketing efforts of Segway representatives, I have noticed that they frequently promote (a) the ability of the Segway to stop quickly, presumably from the pedestrian speeds at which they are often tested indoors, and (b) the speed advantages of the Segway over walking. Well, they can't have it both ways. If the Segway is operated fast enough to provide the mobility advantages of competing products such as bicycles, then the laws of physics will determine its stopping distance. I have not seen anyone from Segway LLC compare, side by side, experimental stopping distances of Segways and modern bicycles operated by competent operators at the same speeds. Either they don't understand the significance of this, or they know that the Segway will not compare well. But I don't need to see an experiment; as a Ph.D. in engineering I know that the force vector diagrams don't lie. Segways won't stop any faster than bicycles at the speeds that their operators want to go.

I've also seen the repeated claim that Segway operators will go slowly among pedestrians and other locations where increased speed may be unsafe. But bicyclists who operate on pedestrian facilities have a very bad reputation for traveling too fast in these situations. This led to their prohibition on pedestrian facilities in many locations. Now consider that the cyclist on the pedestrian facility has the incentive to travel slowly in order to conserve his own energy. The Segway operator does not have this incentive; therefore I conclude that the Segway operators will not travel any slower than typical bicyclists operating on sidewalks - they will probably go faster.

I have seen repeated resistance from Segway LLC to the requirement of proper lights on Segways. In urban areas, both pedestrians and bicyclists suffer higher rates of injuries and fatalities per mile of travel at night. This is why bicyclists are requried by law in all 50 states to use white headlamps in front and red rear lights or bright red rear reflectors. The Segway has a very convenient power source for vehicle lights. Either the Segway LLC lobbyists think Segway drivers will be immune to these visibility-related collisions or they don't care about public safety.

I see frequent contradictions in Segway LLC's approach to the marketplace. Yes, the Segway technology is very cool, but once the novelty wears off Segway LLC must be able to explain why people would rather travel by Segway than by walking, cycling, automobile use, or moped/scooter use. Their inability to do this, by concentrating on the unremarkable ability to travel by wheels on sidewalks, reveals a general ignorance of the transportation marketplace. Those who have studied real-world bicycle transportation in the United States have a better idea of the Segway's market potential than the Segway marketers who must be deluding themselves. People currently travel by faster, more affordable bicycles because (1) they cannot own or operatee cars or motor scooters for legal or economic reasons, (2) they enjoy the exercise, or (3) they cannot find or afford convenient auto parking in urban places. The Segway consumer market is those people who have plenty of money, don't care about exercise, and have difficulty finding car parking spaces where they want to go. I suspect that most of these people are already buying electric bicycles, scooters, and mopeds. That's a pretty small slice of the transportation pie.

What is most disturbing to me is the willingness of the states to pass Segway laws and regulations that are identical to those that bicyclists have been lobbying against for over a hundred years. The bicyclists have defended their own safety and travel rights effectively by promoting at least a minimal accommodation of safe driving techniques and essential equipment requirements in the state traffic laws, against the best efforts of non-cyclists who are mostly ignorant of useful bicycle transportation. Perhaps if there were a significant number of Segway owners, the segway laws would have been written to better serve the interests of Segway drivers. Meanwhile, by acting vigorously to de-legitimize the operation of light vehicles on roadways just because of limited speed capability, the Segway lobby has not made any friends among the cycling community.

-Steve Goodridge

[n/a]

quote:...I can comfortably say that most true fans have a higher regard for Segway's safety performance than can be justified at this time with emperical evidence.

JohnM, u are very quick to arrest me when I state an opinion as opposed to fact. If u want your statement to be taken seriously u have to face the problem of having to define "true fans" in a manner acceptable to a research community which is concerned with empirical evidence (note the spelling of empirical.)

[ftropea]

But you know...

Who am I to argue with someone who has a Ph.D. in physics?

If those are the numbers then I must be mistaken.

Regards,

Frank A. Tropea

[JohnM]

quote:Originally posted by Lawrence
JohnM, u are very quick to arrest me when I state an opinion as opposed to fact. If u want your statement to be taken seriously u have to face the problem of having to define "true fans" in a manner acceptable to a research community which is concerned with empirical evidence (note the spelling of empirical.)


A posting worthy of a 'true fan', IMHO.



Runnin' with the Big Dogs

[bicycledriver]

Frank,

Here are my predictions for your minimum braking distance at 12.5 mph.

12.5 mph is 18.33 feet per second. One G is about 33 feet/sec/sec.

So at 0.6 Gs,

d=0.5a(t^2)

t=v/a

d=0.5(v^2)/a = 0.5*(18.33*18.33)/(0.6*33) = 8.487 feet braking distance.

Add to this your reaction time times your initial speed of 18.33 feet/s to get your total stopping distance.

Do you believe you exceeded 0.6 Gs? Tire adhesion will fail at just over 0.8 Gs on most paved surfaces. I bet you were under 0.4 Gs. So what is wrong here: the above equations, the constants, or your perceived braking distance?

I don't have a Segway available to test, but I do know physics. I have more faith in these scientific predictions than in subjective memory of past experience, as I know my own memories can be highly misleading for myself.

Regards,
Steve Goodridge (who bicycles on roadways about 2000 miles per year, mostly suburban/urban commuting, and whose only two injuries in 20 years involved falls related to poor surface conditions - a pothole and a patch of gravel.)

[bicycledriver]

Frank,

Actually my Ph.D. is in electrical engineering. My specialty was in control systems and robotics, including vehicles and self-balancing systems. I am as impressed with the implementation of the Segway control system as I am aware of its limitations.

-Steve Goodridge
Member, Cary NC Planning and Zoning Board
Bicyclist and Pedestrian Advocate

[Casey]

Is this no longer valid?

"Steve Goodridge
NCBC Vice President"

[ftropea]

BD,

Thanks for revising those numbers.. I think they're getting closer to what my subjective memory remembers...

By the way, I rode the Segway only a few days ago :)

Umm, I'm not sure I have the ability to differentiate between .6 and .8Gs.. Maybe if someone told me what the G forces were as I experienced them, that would help form a frame of reference.

My impression, and again it's a 3-4 day old impression, was that it only took a few feet.. I'm guessing no more than 5 feet... to brake. But like I said, I'm not a person to be arguing this with someone who has earned a Ph.D. in anything :)

By the way, I don't think the consumer version will exceed 12.5mph so you may want to revise your numbers. I don't think even the current industrial/commercial versions exceed 12.5mph... Something to think about.

Regards,

Frank A. Tropea

[bicycledriver]

Casey,

Yes, I'm still vice president of the North Carolina Bicycle Club. I like to rotate my titles in my signatures.

-Steve Goodridge
Chief Scientist, Signalscape, Inc.

[charmed]

quote:Originally posted by bicycledriver

Frank,

Here are my predictions for your minimum braking distance at 12.5 mph.

12.5 mph is 18.33 feet per second. One G is about 33 feet/sec/sec.

So at 0.6 Gs,

d=0.5a(t^2)

t=v/a

d=0.5(v^2)/a = 0.5*(18.33*18.33)/(0.6*33) = 8.487 feet braking distance.

Add to this your reaction time times your initial speed of 18.33 feet/s to get your total stopping distance.

Do you believe you exceeded 0.6 Gs? Tire adhesion will fail at just over 0.8 Gs on most paved surfaces. I bet you were under 0.4 Gs. So what is wrong here: the above equations, the constants, or your perceived braking distance?

I don't have a Segway available to test, but I do know physics. I have more faith in these scientific predictions than in subjective memory of past experience, as I know my own memories can be highly misleading for myself.

Regards,
Steve Goodridge (who bicycles on roadways about 2000 miles per year, mostly suburban/urban commuting, and whose only two injuries in 20 years involved falls related to poor surface conditions - a pothole and a patch of gravel.)


Dear Steve Goodridge,

It has been posted on various enthusiast sites more than once that Segway LLC's own stopping distance figure, at 12.5 mph., is 5 feet. I wish I could verify that with a link (or better yet, some math), but unfortunately I can do neither at this moment. I will research the matter and get back to you. This of course does not take into account reaction time, only braking distance. I'm curious if you consulted with any of the engineers at Segway on the matter of stopping distance. No doubt they would be impressed with your work, and no doubt you are interested in their figures.

I'm curious. Your report is very comprehensive. Were you commissioned (hired) to do it, or did you do it for free? Don't mean to be nosy. I have to assume you are presenting this data for professional reasons, unless you let us know otherwise (bias, I'm sure you understand, must always be taken into consideration, especially when legislation is on the line).

Also, I am also curious about how you quantified, or modeled, the Segway's tires in your estimates. Did you base your figures (friction) on a bicycle-type tire? You mention that you have never ridden a Segway. Have you seen one in person? I would imagine (yes, I am a layman) that the actual footprint and composite makeup of the tire material (which I am led to understand is soft and grippy) would contribute a lot to theoretical stopping distance.

If this is all in your report, forgive me. When I saw your figures for 15 mph (curious why you chose that speed, with 12.5 mph. being the top speed for all models on offer so far), they seemed high relative to the many first hand reports we have read from actual users/riders.

Thanks in advance for any further light you can shed,

Charmed

[yop]

quote:Originally posted by bicycledriver

Tire adhesion will fail at just over 0.8 Gs on most paved surfaces. I bet you were under 0.4 Gs.


What are the parameters behind these numbers? Do they take into account the fact that you lean back when you brake on a Segway? Or the Segway's anti-lock braking system? (I'm assuming the Segway has anti-lock brakes. It certainly has enough computing power for it, and from watching the snow/ice performance video on the Segway web site, it certainly behaves as if it has antilock brakes and traction control.)

Based on my personal experiences, stopping distance on a bike is determined by two things: skidding and getting thrown over the top of the handlebars. On a Segway, the antilock braking system can avoid skidding. Perhaps the tires perform better than bike tires as well (perhaps the antilock brakes and traction control allow the use of softer, "tackier" tires without excessive durability problems). And because stopping on a Segway is controlled by leaning backwards, it is harder to be thrown over the handlebars. The backward lean creates a moment that counteracts the stopping moment.

Perhaps the Segway is able to handle higher braking accelerations because of these factors.

Alternatively, here's another way to raise questions about these numbers: 12.5mph is a fast jog. It's a world-class marathon runner's pace. Tennis players go much faster than this, and manage to stop in just a couple of feet.

[Seeker]

quote:
Yes, the Segway technology is very cool, but once the novelty wears off Segway LLC must be able to explain why people would rather travel by Segway than by walking, cycling, automobile use, or moped/scooter use. Their inability to do this, by concentrating on the unremarkable ability to travel by wheels on sidewalks, reveals a general ignorance of the transportation marketplace.



Hi Steve,

Thanks for the many excellent points you've brought up in the forum.

With regards to the statement above, I would submit that because Segways offer a unique transportation experience, they may capture a segment of the market which no other vehicle/ mode of transportation, is currently able to appeal to. You may be right though, the novelty may wear off quickly, at which point the Segway could be thought of as an expensive toy. It would be interesting to hear whether people who've ridden a Segway for a good period of time, still get a 'kick' out of the experience.

Seeker

[Seeker]

quote:
I would imagine (yes, I am a layman) that the actual footprint and composite makeup of the tire material (which I am led to understand is soft and grippy) would contribute a lot to theoretical stopping distance.



That's an interesting point, Charmed.

Wouldn't a slightly under inflated tire (which a Segway has) yield a better stopping distance than a normally inflated tire ?

Seeker

[Blinky]

Bicycledriver writes...
quote:Here are my predictions for your minimum braking distance at 12.5 mph.

12.5 mph is 18.33 feet per second. One G is about 33 feet/sec/sec.

So at 0.6 Gs,

d=0.5a(t^2)

t=v/a

d=0.5(v^2)/a = 0.5*(18.33*18.33)/(0.6*33) = 8.487 feet braking distance
This is going to be very similar to what YOP has wrote a couple of posts ago in this thread. But I have similar questions too.

I am sure you know how fast 12.5mph feels like. How long do you think it would take to stop on a Segway-HT at 12.5mph having never tried one? There are probably not many things you can compare the Segway-HT.

I know this formula you wrote is your predicted/subjective guess from prior experiences. But what are the outside conditions that you base this formula on other than reaction time?

Do you know the mechanics of the Segway-HT? If so, is this formula based on the Segway's ability to stop.

There has to be variables to this that have not been explored yet.
------------------------------------------
quote:Regards,
Steve Goodridge (who bicycles on roadways about 2000 miles per year, mostly suburban/urban commuting, and whose only two injuries in 20 years involved falls related to poor surface conditions - a pothole and a patch of gravel.)
Was most of this riding on open road? I am sure you use your judgement when riding and avoid 'TAILGATING' when doing so.

[Blinky]

JohnM writes..
quote:But I think I can comfortably say that most true fans have a higher regard for Segway's safety performance than can be justified at this time with emperical evidence. Many will dispute Steve's 'Segway Maneuverability Limitations', basing their arguement on little more than Segway LLC's safety claims ('no mishaps') or their own limited riding experience. Who knows? Maybe they're right. But until Segway LLC can come up with something as simple as braking distances, I
appreciate Steve's analysis.
'Who knows?' is the most absolutely correct way of putting it. Why assume Segway's are safe or unsafe. I think the lack of information that Segway LLC has produced thus far should have us all looking at the people who have actually rode one.

Why not listen to them. I am sure there are negative and positive reviews of the Segway experienced riders(from 1 hour to a 1000hrs<--weskifm is almost there [:p]) that we can base our comments on. Specificially regarding the safety of the Segway-HT.

I wonder how many of those protesters all over the nation have actually rode a Segway. Not to totally insult those people, and to show I am open to how other people feel, I am sure they make some good points about Segway's not being able to fit on their small sidewalks/etc.. They are wrong to quickly judge something they know nothing about.

A point that Ftropea made in his article is also very true. Nothing is "completely "fool-proof",". I am sure you could do a lot more idiotic things on bikes(extreme espn type sports) than you can on a Segway-HT. 12.5mph is not a dangerous speed, in my opinion of course.

As for people with anti-segway sentiment regarding its SEGWAY'S SAFETY with no facts available to use in their arguments, can continue to ride down those streets. Segway will make a difference in our society, there is nothing here to stop them.

[GlideMaster]

In regards to stopping on the Segway tire pressure plays an important part.
From the Training Workbook

Effect of Tire Pressure
The tires on the Segway HT serve two primary functions:
Suspension
Traction

Dropping the tire pressure will soften the ride and increase traction while reducing range.

Tire Pressure

The acceptable limit of tire pressure for the i-series is 15 psi and 15 psi for the e-series without cargo and 22 psi carrying cargo.

I'm sure you know who the tires are by.








quote:Originally posted by Blinky

Bicycledriver writes...
quote:Here are my predictions for your minimum braking distance at 12.5 mph.

12.5 mph is 18.33 feet per second. One G is about 33 feet/sec/sec.

So at 0.6 Gs,

d=0.5a(t^2)

t=v/a

d=0.5(v^2)/a = 0.5*(18.33*18.33)/(0.6*33) = 8.487 feet braking distance
This is going to be very similar to what YOP has wrote a couple of posts ago in this thread. But I have similar questions too.

I am sure you know how fast 12.5mph feels like. How long do you think it would take to stop on a Segway-HT at 12.5mph having never tried one? There are probably not many things you can compare the Segway-HT.

I know this formula you wrote is your predicted/subjective guess from prior experiences. But what are the outside conditions that you base this formula on other than reaction time?

Do you know the mechanics of the Segway-HT? If so, is this formula based on the Segway's ability to stop.

There has to be variables to this that have not been explored yet.
------------------------------------------
quote:Regards,
Steve Goodridge (who bicycles on roadways about 2000 miles per year, mostly suburban/urban commuting, and whose only two injuries in 20 years involved falls related to poor surface conditions - a pothole and a patch of gravel.)
Was most of this riding on open road? I am sure you use your judgement when riding and avoid 'TAILGATING' when doing so.

[JohnM]

quote:Originally posted by Blinky
'Who knows?' is the most absolutely correct way of putting it. Why assume Segway's are safe or unsafe. I think the lack of information that Segway LLC has produced thus far should have us all looking at the people who have actually rode one.

Why not listen to them. I am sure there are negative and positive reviews of the Segway experienced riders(from 1 hour to a 1000hrs<--weskifm is almost there [:p]) that we can base our comments on. Specificially regarding the safety of the Segway-HT.

I wonder how many of those protesters all over the nation have actually rode a Segway. Not to totally insult those people, and to show I am open to how other people feel, I am sure they make some good points about Segway's not being able to fit on their small sidewalks/etc.. They are wrong to quickly judge something they know nothing about.

A point that Ftropea made in his article is also very true. Nothing is "completely "fool-proof",". I am sure you could do a lot more idiotic things on bikes(extreme espn type sports) than you can on a Segway-HT. 12.5mph is not a dangerous speed, in my opinion of course.

As for people with anti-segway sentiment regarding its SEGWAY'S SAFETY with no facts available to use in their arguments, can continue to ride down those streets. Segway will make a difference in our society, there is nothing here to stop them.


Blinky, slow down. Nothing in Steve's analysis is suggesting that he is anti-Segway or wants them banned. Both the legislatures in my New Hampshire and Steve's North Carolina have narrowly defined Segway as a pedestrian device, limiting then largely to the sidewalks. Other states have taken a wider view. New Jersey, for instance, will allow Segways use of sidewalks as pedestrians and the streets as vehicles. Since no one knows the best environment for Segways, and experience with other light, wheeled devices suggests that the streets may be safer, why not opt for the wider definition that allows the Segway to operate as a vehicle?

Runnin' with the Big Dogs

[GlideMaster]

HI Frank, (it's 0400 hrs)

Well where do I start. FIRST I loved the piece on TV last night.

When it comes to the Segway and speed I've never really been able to tell what my exact speed is. As you know when you reach the speed limit programed into a particular key the Segway will "move toward you." When the Segway begins to move toward you are you at the max or approaching the max? "When you are operating below the speed limit, the handlebar stays in approximately the same place." I don't see how anyone could accurately measure the stopping distance of a Segway. You just don't know what speed you're at when the "Speed Limiter" kicks in. I know when it rears back it dosen't feel like 12.5 MPH. I've always noticed that the Segway the the King of Balance uses never seems to rear back when he's ridding. I can tell he is going more than 15 MPH sometimes and yet his Segway always stays in the same safe speed position. I've watched him closely everytime I see a piece and he's ridding and I can tell the characteristics of his Segway are a little more high performance. I don't care what mathmatical equation anyone uses it cannot give an accurate stopping distance of a Segway. Now it may be able to give an approximate range. It has never taken me more than five feet to stop. But then again it's according to how aggresive you want your stop to be. If you pull back hard and fast you can make some very short stops; almost on a dime. But as I always say (see my topic on safety slogans) and remember the 3Rs. No it's not reading, righting and rithmatic either.

Hope this helps Frank. Wonder what are the stopping distances of a bike. Does a bike have a "Speed Limiter." I guess it's called a Human. You could say the same for the Segway.









quote:Originally posted by ftropea

JohnM,

Well.. limited Segway riding experience is probably better than none, so indulge me while I make the following point:

I didn't ride the Segway at more than 12.5mph... and the stopping distance wasn't more than 5 feet for sure. The study calculates that the "breaking distance" on a Segway at 15mph would be 12.5 feet? And that the "stopping distance" would be 34.5 feet?

Now, I admit I didn't travel at 15mph... but those number simply can't be true.

I went 12.5mph.. pulled and leaned back and stopped without losing my balance... and I stopped within a few feet. I didn't experience any uncomfortable forces either...

Believe it or not, it's true.

Weskifm.. you out there? Can you verify what I'm saying? Weskifm has over 50 hours of riding time...


Regards,

Frank A. Tropea

[bicycledriver]

On maximum deceleration:

A simple consideration of the laws of physics reveals that the maximum braking ability of the Segway is limited by the coefficient of friction of the tires on pavement, or the tangent of the maximum lean angle with respect to vertical, whichever is less. On dry asphalt the coefficient of static friction adhesion for rubber tires can be as high as .8 or even .9, but on wet sidewalks it drops to between .4 to .7. Note that if the tires lose friction at high speed the Segway will lose balance and crash, so it is important to stay below these numbers. Thus I suspect it unwise to push the Segway tires beyond .6 Gs from top speed.

The lean angle of the Segway may be the limiting factor. I have never seen a picture or video of a Segway leaning back with an angle tangent of as much as 0.3. I provided braking numbers for both 0.3 and 0.6. I sincerely doubt the 0.6 but I provided it to be generous. (Someone wrote before that bicycles are limited in their braking ability by their ability to flip over the front tire - this is the exact same limitation as the Segway experiences; for the bicycle the body mass angle (tangent of about .6) defines the *maximum* pssible braking, but for the Segway the body mass angle tangent *equals* the braking in Gs.

On braking distance:

Once we have the maximum deceleration rate in Gs, the braking distance is calculated using the basic motion equations we all should have learned in high school. Add to this the reaction time multiplied by the initial speed to get the stopping distance. No amount of clever electronics (and I know a lot about clever motor control algorithms) can change Newton's laws of motion or the motion equations. Talk to Segway's engineers and they will confirm my numbers. I think their past silence on stopping distance may be due to fear over the political implications of the Segway marketing effort.

For more insight I recommend the book _Bicycling Science_ by Whitt and Wilson, MIT Press 1982, 1997, pp 189-214.

I used a top speed of 15 mph because that is the maximum speed defined in the NC traffic law for the Segway type device. In New Hampshire the law states and even higher maximum speed. I believe these are the proper numbers to use because they are what appears in the law, and it is the law that I criticize, not the Segway. Segway may intend to limit commercial Segway speeds to 12.5 mph today, but nothing is stopping them from increasing it in the future if this improves marketability. The first Segway press reports defined a maximum speed of 18 mph and the Segway engineers have speculated even higher speeds. Since the product's software is a moving target, the value written into the law is what I consider relevant when considering the merits of the law.

Steven Goodridge

[bicycledriver]

Some have asked about my motivations and what inspired (or funded) the article. I will answer this now.

As an avid cyclist and member of the bicyclist advocacy community, I am familiar with the best science and research available on cycling safety. I am also familiar with the habits of legislators who tend to ignore the science and resort to taboo and prejudice when writing traffic laws for travel modes that they don't use regularly. Only through lobbying by competent cyclists have the traffic laws been preserved such that they protect safe and efficient cycling on roadways, rather than forcing cyclists to behave as pedestrians on wheels and suffer the greater risks and inconveniences that we know, empirically, are associated with the pedestrian-on-wheels approach to cycling.

The earliest debut of the Segway made it clear to me that it was being marketed as a pedestrian-on-wheels device with the intention of appealing to the taboos and prejudices of those who don't understand the principles of effective bicycle transportation. I felt that this was foolish for Segway LLC, but harmless enough to cyclists since the Segway would not see much consumer use.

Unfortunately, Segway LLC's lobbying effort to screw up the state traffic laws was not so harmlessto cyclists. After cyclists, using their own personal time and effort, spent three generations convincing all 50 state legislatures that cyclists fare best when they act and are treated as drivers of vehicles under the state vehicle codes, Segway LLC comes along and spends money trying to convice legislators and the general public that light (80 pounds?!!) low speed (15-18 mph?!!) vehicles don't belong on streets and should be banished to sidewalks. Gee, thanks.

So I sat down one Sunday and wrote the article I referenced. I drew the pictures and put it all on the web site. It wasn't difficult given my skills and experience. What outrages me is that the lack of competent technical analysis made available to the legislators who passed these unfortunate laws, without the cycling community knowing it was coming. All they had to do is ask.

As I wrote before, I am not against the Segway as a device. The market will decide how useful it is. What I am against are laws that put Segway operators at risk, by either requiring them to do things that are unsafe or failing to protect them when they do things that are safer. The existing Segway laws are a can of worms and will cause quite a spectacle when a court inevitably has to decide who is liable in a car-Segway collision.

Steven Goodridge

[bicycledriver]

It appears from previous posts that drivers are unaware of the Segway's speed. Does it not have a speedometer? I recommend having a cyclist with a properly calibrated bicycle computer ride beside you when conducting experiments. Failing that, you could mount a bicycle computer on the Segway.

To measure stopping distance, drive the Segway at constant speed down a track with markings every few feet or so, and have someone blow a whistle when you reach a random marking of the whistle-blower's choice. Come to a complete stop as fasta as possible when you hear the whistle, and measure your stopping position with a tape measure back to the marking chosen by the whistle blower.

For an interesting experiment, do this side-by-side with a competent cyclist who knows how to use the front brake. Please post the results here for us to see.

Regards,
Steve Goodridge

[bicycledriver]

On Anti-Lock Brakes:

It was suggested that the Segway has anti-lock brakes and that this may reduce the stopping distance of the Segway compared to my theoretical predictions.

My theoretical predictions used the static coefficient of friction for a rolling tire. Once a tire locks up and slides its coefficient of friction is lower, meaning it canot stop as well. Anti-lock brakes return the tire to static friction. The average friction provided by wheels moving in and out of a sliding state is less than that of the static friction case. Since I assumed static friction, the theoretical values I provided are best-case.

Regards,
Steve Goodridge

[yop]

Steve,

You have brought up a lot of different points in this thread. However, we seem to be focusing exclusively on the issue of stopping distance here. Why don't you start some other threads to discuss those other issues you raised?

Back to stopping distance. To begin, the reaction time on the Segway is much better than on a bike or in a car. The Segway taps humans' natural "shy reflex". People naturally lean away from a potential collision. There are no higher order brain processes involved, so it happens extremely quickly. On a Segway, as soon as your brain recognizes the danger, it automatically sends signals to cause the body to lean away. This is in contrast to stopping any other vehicle where your brain needs to recognize the danger, decide to stop, recall how to stop, and then engage the necessary muscles. Two extra steps to stopping a car or bike. And those extra steps are relatively slow. Worse, in a panic situation, those extra steps can be slowed down or even completely short-circuited.

In addition, I think that the tire rubber of a Segway is likely to be tackier than that of a bicycle. For any tire, the design parameters are tackiness and toughness. The tire needs to grip the road, and it needs to have a long enough lifetime. I think the Segway's computerized control will contribute to extending the tires' lifetime. The Segway's computerized acceleration and braking control will prevent both spinning your tires and skidding. Because the tire is protected from these damaging processes, the toughness of the tire will be less of a design priority, thus allowing greater emphasis to be placed on tackiness.

[Casey]

Given the complete absence of performance statistics on the internet for Segway (believe me I have searched every crack and crevice I can find), I can't put up a viable and provable defense against the huge amount of information, correct or not, presented above.

I will say this. Segway has a completely different set of dynamics than that of any other vehicle there is. To try to apply the physics of a bicycle or other vehicle to Segway just simply seems a waste of time. Yes there are general physics laws that apply to it. But the combination of DS, regenerative braking and other factors, including the lack of normal reaction time due to Segways immediate reaction to human emotion precludes making the bicycle to Segway comparison attempted in this thread. In addition, Segway is not a free wheeling vehicle.

I won't engage in a protracted discussion on the subject as I do not have the advanced math knowledge, nor access to necessary testing to prove my point.

But it is very obvious to me that the hypothetical 34.5 foot stopping distance is distorted by a factor of at least two, and probably three. I have no doubt in my mind that a Segway traveling at the speed of 15 miles per hour could easily stop in 15 feet including a reaction time that is miniscule compared to that required to apply stopping action to any other vehicle. In addition if a Segway, moving forward, comes into contact with any obstruction, it instantly reverses AUTOMATICALLY. That is something a bicycle or other vehicle does not do.

For lack of an alternative I have no choice but to wait for proof. But I believe after reading extensivly about Segway including rider reports that my gut instinct on this will be proven true.

[JohnM]

quote:Originally posted by bicycledriver

It appears from previous posts that drivers are unaware of the Segway's speed. Does it not have a speedometer? I recommend having a cyclist with a properly calibrated bicycle computer ride beside you when conducting experiments. Failing that, you could mount a bicycle computer on the Segway.

To measure stopping distance, drive the Segway at constant speed down a track with markings every few feet or so, and have someone blow a whistle when you reach a random marking of the whistle-blower's choice. Come to a complete stop as fasta as possible when you hear the whistle, and measure your stopping position with a tape measure back to the marking chosen by the whistle blower.

For an interesting experiment, do this side-by-side with a competent cyclist who knows how to use the front brake. Please post the results here for us to see.


If any of Manchester's Segwayists are lurking here and would like to try this, on or off your company time, I'm available.

Runnin' with the Big Dogs

[bicycledriver]

yop,

I would counter that competent cyclists (and motorists) have developed their braking skills to the level of a low-level reaction with no higher brain function. An experienced cyclist does not think about how to brake, it becomes instinct to grab both brakes and shift one's weight backward if needed. I suspect that this eliminates any advantage the Segway driver has in terms of reaction time; in fact I still think that the amount of time needed to lean the Segway backward may delay the onset of maximum braking force compared to what can be accomplished by a competent cyclist. However, the cyclist does need to be familiar with how to modulate the front brake in order to avoid an endo. I therefore concede that it is possible that a beginner Segway driver may outperform a beginner cyclist at braking *if* the Segway is capable of an extreme lean angle with a tangent over 0.5.

Of course the way to put this to rest is to have someone do the Segway stopping distance experiment I described under the supervision of an independent observer, and compare them to my results for the corresponding starting speeds. Any takers? If not, I would be glad to do it myself if someone provides me with a Segway.

The stickiness of bicycle tires depends on the purpose of the tire. Racing tires are very sticky in order to handle fast cornering but wear out quickly. The racing tires that came on my 2002 Lemond Zurich are already wearing rather low - I just bought the bike in December and I put only about 800 miles on them. I will be switching to some harder "training" tires for greater range since my cycling is mostly commuting and some weekend pleasure rides - I have never raced. I think I remember the range in adhesion ranges from about .75 to about .9 on dry asphalt for different bicycle tires - I don't have my books with me here at work.

-Steve Goodridge

[Casey]

quote:If any of Manchester's Segwayists are lurking here and would like to try this, on or off your company time, I'm available.


I wish I were there and had a Segway. I would gladly accomodate you. And I am extremely interested in the outcome. It would be great to see someone representing Segway take you up on this. Perhaps John Grohol would like to help in this test. It really is time that someone come forward and put this matter to rest.

Just one thing. Being that you insist on someone good with the front wheel braking on a bicycle, I think the Segway rider should also be an expert with that device. Dean would be an ideal candidate, but there are many Segwayists working in the DEKA and Segway organizations that should be qualified for this test.

In addition, I think it would serve a good purpose to also include a test of an amateur bicyclist tested against an amateur Segwayist.

Here's hoping someone will answer your challenge/offer.

[Casey]

quote:An experienced cyclist does not think about how to brake

Come on now Steve. That is simply wrong. A bicyclist requires the same reaction time a car driver does. And even race drivers will assure you that there is a reaction time.

[yop]

quote:Originally posted by bicycledriver

I would counter that competent cyclists (and motorists) have developed their braking skills to the level of a low-level reaction with no higher brain function.


No, that's not true. The "shy reflex" happens at a much lower level (and is therefore much faster). The shy reflex evolved at a very early stage of evolution. For a demonstration of how fast the shy reflex is and how early in evolution it came about, try to slap a housefly out of the air.

[bicycledriver]

Casey,

The Segway marketing team should be proud that they have been able to convince you, with their propaganda, that the Segway defies everything that scientists say they know about vehicles. I recognize the origins of all of the arguments you make in previous marketing materials from Segway LLC.

In terms of forward/backward acceleration and deceleration and braking, the Segway is an inverted pendulum. Students who study control systems design study inverted pedulums in their beginning classes. Like a unicycle, all of the forward/backward acceleration forces during normal operation must be applied through the tire to the ground, and are thus limited by both tire adhesion and lean angle. Nothing about the Segway changes this. But during collision, some of the momentum and kinetic energy will be transfered to the object struck. How much depends in part on how tall the object struck is. If the object struck is above the center of mass of the Segway and driver, then the Segway driver will tilt backward and more force will be applied to the wheels for braking. At a walking speed this will merely jostle an adult-sized pedestrian who is struck at chest level. But if the collision point is *below* the center of gravity of the Segway and driver, such as a dog, child, hydrant or park bench, then the driver and Segway will rotate upward around the contact point, unweighting the drive wheels and making them useless for braking. Here all of the kinetic energy will be tranferred to things other than the braking system.

If people are so certain of the safety of the Segway, then they should volunteer themselves as guinea pigs for crash tests. Perform one collision test at 15 mph with the volunteer pedestrian standing blindfolded. Repeat the same test with the pedestrian squatting faced away to tie his or her shoe. What happens?

Regards,
Steve Goodridge

[bicycledriver]

yop,

I studied the biology of natural nervous systems in humans and animals as part of my graduate research in robotic control systems.
(some old papers of mine are posted at http://sggoodri.home.mindspring.com/prof.htm). I am familiar with the relative speeds of reflexive, reactive, and deliberative motor actions depending on the lengths of the corresponding neural pathways and the performance of the axons (which is different for different types of animals). My early work on automomous robot control was based on low-level reactivity modeled after natural systems.

The largest part of the reaction time involves the recognition of a threat that requires braking. I theorize that this will be the same for Segway drivers as it is for other types of drivers. The reason is because if Segway drivers are too "trigger happy" on the brakes, they will slow down unnecessarily for all types of non-threats. This will reduce their convenience of travel. The Segway drivers must habituate to non-threats the same way that other drivers do. This process is not any different just because the driver is on a Segway.

What is different on a Segway is the type of twitch required to initiate braking. The bicycle requires a mere twitch of the hand. One of the advantages of hand brakes on a bicycle over any kind of pedal brakes is that it is possible to accelerate a bicycle while one's fingers are loosely placed over the brake levers, ready to brake in an instant. This is standard practice for cyclists pedaling through intersections, where drivers have a bad habit of turning directly in front of the cyclist (the leading cause of car-bike crashes for adult cyclists.)

Regards,
Steve Goodridge

[ftropea]

Weskifm wrote: "It has never taken me more than five feet to stop."

That's pretty much what I felt trying out a Segway-HT for myself. The stopping distance was very short.. I'm willing to say it was around 5 feet...

Note: Weskifm has over 50 hours of Segway riding experience.

But according to bicycledriver's numbers, we're both wrong weskifm. How can we account for this?

Regards,

Frank A. Tropea

[Casey]

Steve, as I said, I won't get involved in an unprovable situation. With time we will see what the real world results are. And as I also said, I have no doubt my instincts are right on this. Segway simply is not comparable to a bicycle.

quote: I recognize the origins of all of the arguments you make in previous marketing materials from Segway LLC.

On this you are very wrong. I have been to the Segway LLC site a total of possibly 5 minutes. My information is from other sources on the net that I have found reference to Segway. Some is 3rd hand propaganda which is obvious and I reject out of hand as hype. I am influenced mostly by watching Dean Kamen as a pro, and TV interviewers as amateurs. Watch those, including 60MinII from Wednesday and the Dec3, 2001 GMA program, and you will see the operators come to almost instant stops as well as spin around and go back from the direction they came. That is not propoganda and is easily observed.

I am also a bicycle rider (no clubs) still owning a 10 speed Ross and 10 speed Raleigh (I am not rich so couldn't afford the designer brands) But I gave it up a few years back due to physical problems. I am very aware of bicycle behaviour and see no comparison between the way a bicycle and Segway act and react to their riders.

[yop]

Try this scenario:
You're riding along at 12mph. Suddenly, something flashes in front of you, suddenly blocking a part of your field of vision. You reflexively lean away.

Now, two possibilities:
1) The "vehicle" you are riding is a Segway. You slowed down when you leaned away. Ha ha. Turns out it was just a leaf falling from a tree. Nothing to worry about. Speed up again and continue on your way.
2) The "vehicle" you are riding is a bicycle. You didn't slow down at all because there was no time to identify the threat, decide to squeeze the hand brakes, and engage the appropriate muscles. Oh well, it was only a leaf, anyway. Good. You didn't slow down at all, so you didn't lose any time.

[bicycledriver]

I should say something nice about Segways in order to avoid sounding like I am anti-Segway, which I'm not.

I think Segways may be very useful those who need to move cargo in places designed for pedestrians. They may also afford mobility enhancement to police and other authorized persons who need to move at high speed through pedestrian spaces under special circumstances.

My concern is limited to the difficulties that arise from denying Segway operators the legal rights and responsibilities of drivers of vehicles when those Segway operators travel at speeds that are fast enough to make the Segway useful enough for personal transportation to compete in the personal transportation marketplace.

Regards,
Steve Goodridge (Who will be in Manchester, NH on the Friday after Thanksgiving in case anyone wants help conducting a stopping distance test.)

[Casey]

quote:Regards,
Steve Goodridge (Who will be in Manchester, NH on the Friday after Thanksgiving in case anyone wants help conducting a stopping distance test.)

As I told John, I sincerely hope someone takes you up on that. I can't quite understand why Segway LLC has not done public testing to avoid the kind of speculation that has shown up in this thread and other web discussions. Good luck on finding someone to assist you in getting this done. Maybe a call to Segway would get some results (or maybe not given the way manufacturers ignore the public now).

[bicycledriver]

Casey,

I watched the original GMA broadcast when it aired. I noticed that they were traveling under 8 mph, and when near one another they were traveling at or under 5 mph. The collision tests looked like they were at about 2.5 mph. They are traveling at mostly pedestrian speeds in pedestrian areas. At such speeds I could stop a bicycle on a dime, too. But why would I want to go so slowly? Commuter cyclists go faster because they can. So will commuter Segwayists.

The very low demonstration speeds (Segway LLC purposely reduced the speed limiters on the early demo units) are a lot different from traveling at the 15 mph and 18 mph speeds allowed by the NC and NH Segway traffic laws, and used in Segway LLC's marketing literature to sell the convenience benefits of the Segway for personal transport. Remember, braking distance and kinetic energy increase in proportion to the square of the vehicle speed.

Regards,
Steve Goodridge (just the messenger)

[bicycledriver]

quote:Originally posted by Casey
I can't quite understand why Segway LLC has not done public testing to avoid the kind of speculation that has shown up in this thread and other web discussions.


I speculate that realistic stopping distance numbers would undermine Segway LLC's efforts to lobby for pedestrian status in the state traffic laws. The pedestrian lobby would use these numbers as evidence against the allowance of Segways on downtown sidewalks.

Once all the states have changed their traffic laws, I expect this to change. *Somebody* objective will eventually test one of these suckers enabled for the top speed allowed by the statute.

Steve Goodridge

[Casey]

quote:The pedestrian lobby would use these numbers as evidence against the allowance of Segways on downtown sidewalks.

I doubt the real statistics could be as damaging as the hypothetical numbers being bandied about by the anti-Segway protesters.

[yop]

A truly representative test needs to be able to engage the shy reflex. The test that Dr. Goodridge outlined earlier in this thread would not be appropriate. The stopping distance in response to a whistle would be appropriate if you wanted to know how fast someone could respond to "Honey! You forgot your briefcase!" A more elaborate test needs to be done to see how the Segway performs when a car door opens suddenly in front of the rider.

[Seeker]

quote:
Steve Goodridge (Who will be in Manchester, NH on the Friday after Thanksgiving in case anyone wants help conducting a stopping distance test.)


Hi Steve,

I might have missed it, but have your calculations taken into account the fact that the under inflated Segway tires would result in a better stopping distance than normally inflated bike tires ?

Seeker

[n/a]

quote:My concern is limited to the difficulties that arise from denying Segway operators the legal rights and responsibilities of drivers of vehicles when those Segway operators travel at speeds that are fast enough to make the Segway useful enough for personal transportation to compete in the personal transportation marketplace.


I share your concerns for safety and responsibility Steve. I think it is in Segway LLC's rational self interest to do likewise. Therefore I welcome intelligent critical analyses.

But I also want Segway to get a chance to be tried out and to make a positive impact in the transportation market. As with all potential remedies to problems and illness, the costs have to be weighed against the benefits, the effects against the side effects. There is always some risk involved. I think Segway should be given enough rope to hang themselves if they are being to wreckless or to prove that their transporters are a viable solution to some major problems.

As I have pointed out, Segways are still being tested and the results wont be in for a while. Some tests have not even been started yet. Those test results will likely impact the way in which the consumer models will be launched on the mass market. Analysies like yours may help them make up their minds.

[JohnM]

quote:Originally posted by Casey

quote:If any of Manchester's Segwayists are lurking here and would like to try this, on or off your company time, I'm available.


I wish I were there and had a Segway. I would gladly accomodate you. And I am extremely interested in the outcome. It would be great to see someone representing Segway take you up on this. Perhaps John Grohol would like to help in this test. It really is time that someone come forward and put this matter to rest.

Just one thing. Being that you insist on someone good with the front wheel braking on a bicycle, I think the Segway rider should also be an expert with that device. Dean would be an ideal candidate, but there are many Segwayists working in the DEKA and Segway organizations that should be qualified for this test.

In addition, I think it would serve a good purpose to also include a test of an amateur bicyclist tested against an amateur Segwayist.

Here's hoping someone will answer your challenge/offer.


I sent a proposal to DEKA/Segway 11 months ago, challenging DK to a race from the top of Strawberry Hill in Bedford to his office in the Manchester Millyard. Segway vs Bicycle. Diane Sawyer waving the checkered flag. I even offered to pick up the tab at a post-race breakfast. I never got a reply, but within a few days he was on local radio saying,
quote:
It (Segway) certainly doesn't have the speed of any of the other transportation devices we talked about. It's certainly not even going to compete for speed with a bicycle.


I don't think there's the slightest posibility that DK would ever accept a head-to-head challenge. Speed, braking, anything that might show a Segway weakness. And in all fairness there are areas where a Segway excells, like, slow speed maneuverability, and I'd never rise to a challenge.

And trust me, I'm just a 53 year old amateur with a lot of miles on my odometer. Only one race, Mt. Washington Hillclimb 1988, and I came in dead last. (Hey, at least I finished!) I'd don't even profess to be a braking expert. Just a survivor of an environment that Kamen doesn't think bikes are suited for.

Runnin' with the Big Dogs

[bicycledriver]

quote:Originally posted by yop

A more elaborate test needs to be done to see how the Segway performs when a car door opens suddenly in front of the rider.


Very good example. Cyclists have died this way, which is why bicycle driver instruction classes and publications teach cyclists to never ride within the door zone. Of course, the uneducated cyclist still do, and some road engineers are so irresponsible as to mark bike lanes in the door zone. This makes it harder to teach proper cycling and encourages harassment of competent cyclists.

But here in NC, a Segway driver is not legally allowed to use the street if a sidewalk is available. Very few roads that are urban enough to have on-street parking lack sidewalks, but some do. If there is no sidewalk, the Segway driver is required by NC law to travel against traffic. This makes him much more likely to get nailed by oncoming traffic and right-turning traffic, but offers the minor advantage of being more visible to people about to open car doors. The Segway driver on such a road must choose among three options:

1. Drive slowly enough to see inside every car and stop in time if a door opens. This is about 5 mph if there are a lot of cars.

2. Stay out of the door zone. This places the Segwayist farther into the lane of oncoming traffic, unlike the cyclist who can drive with traffic. The Segwayist must then get out of the road when a car comes, since pedestrians are required by NC law to yield roadway space, but cyclists are not. The Segwayist may not have anywhere to go but the door zone.

3. Drive in the door zone at full speed and hope for the best.

I would much rather have the rights of a driver when driving a Segway, as this would allow me to travel with traffic and stay outside of the door zone while letting the overtaking drivers move into the next lane to pass me.

I would be happy to replace the acoustic stimulus in the stopping distance test with a visual stimulus. It would take more effort but it would be a better test.

Steve Goodridge

[ftropea]

Bicycledriver wrote:

quote:
...
Unfortunately, Segway LLC's lobbying effort to screw up the state traffic laws was not so harmlessto cyclists. After cyclists, using their own personal time and effort, spent three generations convincing all 50 state legislatures that cyclists fare best when they act and are treated as drivers of vehicles under the state vehicle codes, Segway LLC comes along and spends money trying to convice legislators and the general public that light (80 pounds?!!) low speed (15-18 mph?!!) vehicles don't belong on streets and should be banished to sidewalks. Gee, thanks.
...


BD, I appreciate you being honest about your motivations.

JohnM, is that your motivation as well?

Both of you are undoubtably bicycle experts and enthusiasts... If you could accomplish one of the following goals, which would you choose?

1) Segways are limited to streets and bike lane access.

2) Bicycles are allowed on sidewalks.

Regards,

Frank A. Tropea

[ftropea]

If you're worried about maintaining your street status and your rights to "drive" your motorless bicycle, I don't think bicyclists have anything to worry about...

People already know how hazardous bicycles are... Those same generations that were fighting for "driver" rights have proven this already. If they're currently banned to the streets where you live, it'll likely remain that way. However, we don't have any experience with Segways yet - although that should change once they begin to sell these things to the world.

What are you worried about specifically? How will Segway use harm bicyclists? I think bicycles will retain their rights. People will make comparison between you guys and Segwayers... but in the end, it'll be up to the Segway riders themselves to decide their own fate... just like you guys did.

Regards,

Frank A. Tropea

[ftropea]

By the way, BD.. in case you missed it, Weskifm (who has more Segway riding experience than all of us combined) thinks he can break in under 5 feet from full speed, for whatever that's worth... That was pretty much my experience as well, although now I'm 4 -5 days removed from my Segway ride :) Memory.. is.. beginning.. to.... fade....... ahhh......... where am I? :P

Regards,

Frank A. Tropea

[Seeker]

quote:

I don't think there's the slightest posibility that DK would ever accept a head-to-head challenge. Speed, braking, anything that might show a Segway weakness. And in all fairness there are areas where a Segway excells, like, slow speed maneuverability, and I'd never rise to a challenge.



Hi John,

If bikes can attain higher speeds, wouldn't this be a good argument for Segways being allowed on sidewalks, but bikes not being allowed on sidewalks ? Maybe Kamen would not be concerned about the Segway being as fast as a bike for this reason.

Seeker

[bicycledriver]

Frank,

North Carolina's statewide vehicle code gives bicyclists the legal rights and responsibilities of drivers of vehicles. Cyclists are allowed on all roadways except fully controlled access highways, i.e. freeways, or roads that have posted minimum speed limits (which are invariably fully controlled access highways). Experienced cyclists are happy with this status because it allows us to travel in maximum safety anywhere we want to go.

Bicyclists are allowed to operate on sidewalks except where prohibited by local ordinances. These ordinances have been passed in certain areas where the locals felt that cycling on sidewalks would endanger pedestrians. Experienced cyclists agree with this legal policy, but warn novice cyclists that they should be extremely careful when cycling on sidewalks, and recommend cycling on roadways instead.

A few localities have passed laws forcing cyclists to operate on sidewalks instead of roadways. These laws were passed to increase convenience for motorists. Experienced cyclists lobby heavily against such ordinances because they create greater danger and inconvenience for most competent cyclists. I managed to get such an ordinance repealed in the town of Cary, NC where I live.

The law created for Segways in NC defines them as pedestrians. Segways are prohibited from roadways, including bike lanes, if a sidewalk is present. If no sidewalk is present then the Segway driver is required to operate against traffic and yield to all oncoming vehicles. This includes bicycles or other vehicles in bike lanes, since pedestrians do not have right of way over drivers in bike lanes.

I believe the ideal law for Segways during this experimental period would treat them as electric bicycles. They would be allowed on roadways, where their drivers would be required to obey the traffic rules that apply to drivers of vehicles, and they would be allowed to operate on sidewalks, where they would be required to yield to pedestrians. Sidewalk cyclists and sidewalk Segwayists would be given the legal rights and responsibilities of pedestrians at crosswalks, which would require operating at pedestrian speed at these locations.

In those areas where sidewalk cycling is prohibited by local ordinance, a permit process could be created to allow experimental use of Segways in these areas by permit applicants. If the localities found that Segways were incompatible with pedestrians in these areas, the permit process could be ended. Alternatively, the state could enact a temporary law preventing localities from prohibiting Segway use on sidewalks, and monitor the conflicts. If after a trial period the communities found that Segway use on downtown sidewalks was not unreasonably hazardous, the state law could become permanent.

Given what I understand about the operation of light traffic in urban areas, I believe that this is the most ethical and scientifically defensible way to allow experimentation of Segways on public streets and sidewalks without forcing Segway operators into endangering themselves or inviting them to endanger others.

Regards,
Steve Goodridge

[bicycledriver]

Uphill, a Segway can probably go faster than most casual bicyclists, and maybe some avid cyclists as well. Downhill, most casual bicyclists will probably go faster. On level ground, most utilitarian cyclists travel between 12 and 18 mph, which is similar to the range of speeds defined for Segways in the state laws. I don't see much reason to use potential travel speed as a reason to prohibit Segways from the roadway portion of ordinary surface streets. Horsedrawn carriages, parking enforcement vehicles, construction vehicles, and farm tractors use roadways at speeds this slow or slower. What does become important is nighttime visibility equipment such as bright rear reflectors and lights.

As for prohibition of vehicles on sidewalks, I don't have strong feelings about this except that I support enforcement of existing laws that require drivers to yield to pedestrians on sidewalks. I also point out that the sight lines and surfaces for pedestrian facilities are designed for pedestrian speeds - that is, where sight lines and surfaces on pedestrian facilities were given any thought at all. This is much different from roadways, where much greater attention is given to design. Drivers of light vehicles use pedestrian facilities at their own peril, and will need to travel more slowly, at less convenience than is possible on roadways under most circumstances.

Steve Goodridge

[JohnM]

quote:Originally posted by ftropea

If you're worried about maintaining your street status and your rights to "drive" your motorless bicycle, I don't think bicyclists have anything to worry about...


Frank, you'd be surprised. Would you worry about Oprah if she were anti-Segway? A couple years ago Oprah had a show in the works that was proposing bikes be banned from city streets. That woman's influence is way out of control. (If I were Dean Kamen, I'd be sending her flowers. Get Kemper's book on her list and he's golden.)
http://www.bikeleague.org/educenter/aaoprah.htm
It's a constant battle. Just look at the anti-bike feelings that are periodically unleashed over on the 'other' forum. Its scarey, but those people vote.

I've said this before, that Segway supporters could take a lesson from bike advocacy groups. Many of the issues are basicly the same. As soon as machines make it into consumer markets, you guys are going to have to get organized and fight for every piece of pavement you can get. And since you have no statistical history of your own, borrow what you can from us. Right now Kamen is promoting the uniqueness of Segways to carve out a market, but promoting the similarities to already approved devices might help him gain wider legal acceptance. In the long run, Segways and bikes appeal to two different market demographics anyway. He has nothing to fear from bicyclists, but plenty to gain. And everyone wins if a Segway or bike displaces a car.

Relying on profit-driven manufacturers to promote your interests is not always the best way to go. As much money as Kamen has to give to politicians, he still has only has one vote.

Runnin' with the Big Dogs

[Blinky]

JohnM writes..
quote:I've said this before, that Segway supporters could take a lesson from bike advocacy groups. Many of the issues are basicly the same. As soon as machines make it into consumer markets, you guys are going to have to get organized and fight for every piece of pavement you can get. And since you have no statistical history of your own, borrow what you can from us. Right now Kamen is promoting the uniqueness of Segways to carve out a market, but promoting the similarities to already approved devices might help him gain wider legal acceptance. In the long run, Segways and bikes appeal to two different market demographics anyway. He has nothing to fear from bicyclists, but plenty to gain. And everyone wins if a Segway or bike displaces a car.
Why use the same lessons from bike advocacy groups? You guys are struggling. If Segway-HT was made from a bike, god only knows what the bike community would do. God forbid Segway did that!

If I were fighting with a bike advocacy group who have been fighting from 1817 to now to fight for every inch of street space to ride I would probably be a little upset at Segway LLC too because of all their progress so far in the United States. And if this was happening to me http://www.drmirkin.com/fitness/8733.html I would most certainly be upset too :).

As for ripping into Segway for using money and buying their way to getting the legislation they want, so be it. If it is true and since there is no proof of this, I can only assume that bicycle advocacy groups have done the same.(UNLESS YOU CAN PROVE OTHERWISE, Put you in a Pro-Segway role 'How does it feel?') For over a hundred years no less(kind of sad, especially with your ongoing battle for your "fight for every piece of pavement you can get").

Isn't this enough (http://www.bikefed.org/tea-21.htm). What else do bike advocacy groups want? Why use the Segway-HT when it has nothing to do with bicycles? Stop associating these two very much different groups.

Segway riders will use the side walks and bike riders can use the streets. Its not like Segway's are kicking you guys off. It is getting tiring that Segway-HT is not safe with no proof to prove it or disprove it. 12.5mph is fast, but lets not get ridiculous. From what we do know from actual USER EXPERIENCES, the Segway can stop 4-5 feet at its top speed.

If you can prove otherwise, then submit your proof. Thanks for your time.

[bicycledriver]

Blinky,

My own concern as a bicyclist advocate (note that I am not a bicycle advocate - I don't care how many people buy bicycles, I only care about the conditions experienced by bicyclists, which is a big difference) is that the lobbying effort by Segway LLC to make the states classify Segways as pedestrians will trickle over into the government's and public's treatment of cyclists, by encouraging people to think of cyclists as pedestrians-on-wheels. The pedestrian-on-wheels paradigm is very dangerous to cyclists because it encourages prohibition from roadways and encourages behavior that is more dangerous than operating as the driver of a vehicle. Pedestrians-on-wheels also suffer much less convenient travel and numerous barriers to the destinations they want to reach in the real world.

I am also concerned for the welfare of the Segway drivers themselves. My analysis of the maneuverability of Segways operated at cruising speed, and my observation that high speed is important for making a speed-enhancement device useful enough to be popular with the able bodied public, leads me to the conclusion that Segway drivers will suffer many of the same crashes that bicyclists experience. I therefore believe that the ethical solution is to teach Segway drivers how to travel efficiently while they minimize their crashes, and to make sure that the traffic laws allow and encourage Segway operators to travel efficiently and minimize their crashes.

Unfortunately, the Segway LLC lobbying effort has done great harm to Segway drivers in some states, such as in North Carolina. Here the law prohibits Segway drivers from traveling safely at their top cruising speed, i.e. operating with traffic, and instead requires less safe operation, i.e. operating against traffic or on sidewalks where present. This makes it impossible to teach safe and efficient Segway driving. Those Segway operators who obey the new law will suffer higher crash rates than those who disobey the law, but those who disobey the law and follow the rules for drivers of vehicles will automatically be held liable for those collisions that are in actuality caused by the errors of other road users. This is what the bicyclist advocacy community knows about bad traffic laws and the effects of taboo and prejudice in the law enforcement and judicial system. Segway LLC could heed our warning, or they could continue to pursue the Segwayist-inferiority-based pedestrian-on-wheels paradigm and let Segway drivers suffer the consequences. I urge Segway LLC to study the real-world car-bicycle collision reports and bicyclist injury statistics and extrapolate how these may or may not be relevant to Segway drivers. I urge that this be done with scientific objectivity and not with the blindness and giddy optimism that appears to afflict the market projections for consumer Segway sales.

Steven Goodridge
http://humantransport.org

[Casey]

You may consider this irrelevant. But in a casual conversation with my wife this morning as we were taking our daily walk, I mentioned the concern bicyclists are expressing concerning Segways affecting bicyclists.

Her immediate response was to the effect "how can one have anything to do with the other, they are two completely different things".

I mention that, because I believe that would be the reaction of most anyone who has little interest in Segway. She however has been very much exposed to Segway because of my interest in it. By the way, she too was a bicyclist during the same period of our lives when I was. She also has no ill feelings toward bicyclists or bicycles.

[bicycledriver]

Casey,

I am certain that there is no intention by anyone at Segway LLC to do harm to cyclists, and that the opposite is likely true. I believe these are inadvertent, unintentional side effects. Cyclist advocates themselves have learned the hard way that promotion of alternative (non-roadway) facilities for light vehicle use typically results in reduced legitimacy of light vehicles on roadways, even though roadways are the only facilities that go everywhere that drivers of light vehicles want to go, and roadways provide safer and more efficient travel for light vehicles in most situations. Promotion of sidewalk-only use for Segways reinforces the motorist-superiority superstition that plagues American society. It makes automobile use even *more* attractive, not less, relative to any of the lighter alternatives.

Steve Goodridge

[JohnM]

One last try.

Segway is the new kid on the block, inexperienced. The various state governments have written laws that put Segway in a box. Bicyclists look at that Segway box and see two things. One, its an even smaller box than the one they have been put in. And two, the box has some nasty things in it. Inexperienced Segway enthusiasts are so happy that they got a box at all that they don't realize that they have been short changed. The bicyclists are fearful that the government may try (again) to take away their bigger box (which took years of effort to assemble) and cram them into a small nasty box, like the Segway box.

It may be in the Segway enthusiast's best interest to carefully look at the recent legislation and ask, 'Is this the best that I could get?' I'm not suggesting that 'one box fits all' and that Segways be shoehorned into the bicycle box. But if you don't ask for better laws now, with full and safe access to the streets (like bicycles), everyone may suffer later.

--------------------------------------------

Frank, you asked about my movation. Fair question.

I've lived in Manchester NH for 25 years, almost half my life. I feel that Dean Kamen/FIRST/DEKA/Segway/whatever are good for Manchester. Kamen's success has a trickle-down effect in the community. I want his projects to succeed. The fact that I personally have no use for a Segway doesn't mean I don't want it to succeed as well. (And I do think its cool that on a quick lunch-time ride downtown today, I saw 3 Segways.) But as a long time urban bike rider I see serious problems with some of the Segway laws being approved, especially those that label the Segway as a pedestrian. I know from exerience that 'Cyclists fare best when they act and are treated as drivers of vehicles' (the cycling advocate's mantra) and would extend that rule to Segways used in the street as well. It really works, trust me. Treating a Segway on the street as a pedestrian, rather than vehicle, is troubling to me because in most communities the sidewalks eventually end and riding in the street in inevitable. This is going to put Segway riders in jeopardy unless handled in a vehicular manner. Being placed in danger is not good for the Segway rider, Segway LLC and ,trickling down, Manchester. Other issues, like Segway's sideway use, will sort themselves out at the local level and are of a lesser concern. But as I said above, the state laws should be looked over carefully to be sure that they are the best that Segwayists (not necessarily Segway LLC) can get.

A secondary motovation is to smack upside the head anyone who badmouths bicycles. We're all in this together folks. Every bike and Segway is one less car on the streets. Please work with us. Failing to recognize our common interests won't help in the long haul.





Runnin' with the Big Dogs

[n/a]

quote:Promotion of sidewalk-only use for Segways reinforces the motorist-superiority superstition that plagues American society. It makes automobile use even *more* attractive, not less, relative to any of the lighter alternatives.

That may be a very good point Steve. If Segway LLC promoted road use for for Segways at an early stage, would that not increase the risk of accidents and injuries to Segway rideres, thereby increasing the risk of Segways being considered dangerous? Did I miss some something?

quote:We're all in this together folks. Every bike and Segway is one less car on the streets. Please work with us. Failing to recognize our common interests won't help in the long haul.


JohnM, lets assume for a moment that the Segway people have some good reasons for not forming a coallition with cyclists. Any suggestions as to what those reasons might be?

BTW JohnM, did u notice what our expert Steve, said about the speed of bikes vs. Segways?

quote:Uphill, a Segway can probably go faster than most casual bicyclists, and maybe some avid cyclists as well. Downhill, most casual bicyclists will probably go faster. On level ground, most utilitarian cyclists travel between 12 and 18 mph, which is similar to the range of speeds defined for Segways in the state laws.

[JohnM]

quote:Originally posted by Lawrence
quote:We're all in this together folks. Every bike and Segway is one less car on the streets. Please work with us. Failing to recognize our common interests won't help in the long haul.


JohnM, lets assume for a moment that the Segway people have some good reasons for not forming a coallition with cyclists. Any suggestions as to what those reasons might be?

BTW JohnM, did u notice what our expert Steve, said about the speed of bikes vs. Segways?

quote:Uphill, a Segway can probably go faster than most casual bicyclists, and maybe some avid cyclists as well. Downhill, most casual bicyclists will probably go faster. On level ground, most utilitarian cyclists travel between 12 and 18 mph, which is similar to the range of speeds defined for Segways in the state laws.


Reasons? Segway LLC is carving out a new market and wants to stress the uniqueness of their machine, ie, that its unlike anything else that's come before. Perhaps that's a legitimate marketing approach, but I really think the demographics of the potential Segway buyer and the urban bicyclist are so different that they shot themselves in the foot. Especially when DK badmouthed bikes in Time magazine the week of the reveal. That got me, a long-time Kamen supporter, ticked off at start. (I softened a bit later in the week when he acknowledged that bikes were faster.)

Speed: It was really more than just brute speed that enabled me to out pace the Segways on the climb up Manchester's East Brook Street. If the Segways had been in the street they might have had a chance. But they had to cross Canal Street as pedestrians, dealing with high curbs and auto traffic. Then the sidewalk up Brook Street was narrow and rough, there were more curbs at several driveways and the block was dark. (Neither Segway had any lights, I was lit up like a Christmas tree.) The pedestrian Segways could not use their 12.5mph max speed safely in that pedestrian sidewalk environment. That's why the vehicular bicycle ridden in the street will be faster (and probably safer)in most situations. If you want to use that 12.5mph potential, you'll have run with the big dogs.

Runnin' with the Big Dogs

[GlideMaster]

Frank or should I say (Father forgive me for I know not what I say).

Well I rode today and I tried to pay attention to the stopping distances. I must admit I was very wrong about the stopping distances. When I reached what I thought might be max speed with the red key it took at least 10 feet or more to stop. I don't usually ride at max speed unless it is a clear area with nothing to obstruct my progress or endanger me or anyone else or anything else.
I did give it several hard stops and I do think it would be hard to stop it at max speed (12.5 on the i-series) in less than 10 feet. I was attempting the aggresive stops on an asphalt parking lot with a cold but dry surface. I also rode in a little water off and on and some sand and on bumps, loose gravel, jumped off some curbs and did some slight inclines and declines not to mention backward spins.

I rode today in the cold about thirty something degrees, had gloves but no hat. It was coooooold. Well the first thing I have to say is I rode a fully charged Segway for fifty minutes. Then I got the provebial Icon Bingo C-4 or number five which states "Slow to a stop and dismount. Battery packs too low to allow continued operation. Segway HT will decelerate to zero speed, stick shake and shut down." I did not ride it that hard I don't think. I wonder was it the cold that contributed to the fast decline of the battery. Glad I did not get stranded. Soon as I saw that all of the battery bars were gone and the Face had turned red I knew it was time to dismount; plus it started to slow down and rear back. The Segway had been charging for several days and all indicators were go. The Participant Workbook states "Battery Safety, Charging and Storage Our batteries will effectively discharge (i.e. power the machine) until they reach 57 degrees Celsius(135 degrees Fahrenheit)."

<center>Always remember when you ride.</center>

<center>Responsible Riders Ride Segway</center>
<center>and </center>
<center>Segway Riders Ride Responsibly</center>

[n/a]

quote:I rode today in the cold about thirty something degrees, had gloves but no hat. It was coooooold. Well the first thing I have to say is I rode a fully charged Segway for fifty minutes. Then I got the provebial Icon Bingo C-4 or number five which states "Slow to a stop and dismount. Battery packs too low to allow continued operation. Segway HT will decelerate to zero speed, stick shake and shut down." I did not ride it that hard I don't think. I wonder was it the cold that contributed to the fast decline of the battery. Glad I did not get stranded. Soon as I saw that all of the battery bars were gone and the Face had turned red I knew it was time to dismount; plus it started to slow down and rear back. The Segway had been charging for several days and all indicators were go. The Participant Workbook states "Battery Safety, Charging and Storage Our batteries will effectively discharge (i.e. power the machine) until they reach 57 degrees Celsius(135 degrees Fahrenheit)."

I wonder how long it will take the anti-Segway people to post this on TIQ and have a heyday with it.

Thanks for posting that Weskim, even if it is not good news. Perhaps this info deserves its own thread?

[JohnM]

quote:Originally posted by ftropea
Both of you are undoubtably bicycle experts and enthusiasts... If you could accomplish one of the following goals, which would you choose?

1) Segways are limited to streets and bike lane access.

2) Bicycles are allowed on sidewalks.


This is a bit like asking , "Do you still beat your wife?"

I wouldn't want to accomplish either.
1. Segways should have all the rights and responsibilities that bicyclists have AND sidewalk access that is compatible with pedestrian safety. Its up to individual communities to determine that compatibility.
2. IMHO the only bicycle riders that belong on sidewalks are young kids who lack the ability to make the kind of decisions needed for street riding. There are plenty of stats showing that bikes do better in the street. I think the current NYC Laws are a bit harsh, but I do not condone adult bicyclists riding on sidewalks.

Runnin' with the Big Dogs

[bicycledriver]

quote:Originally posted by Lawrence
If Segway LLC promoted road use for for Segways at an early stage, would that not increase the risk of accidents and injuries to Segway rideres, thereby increasing the risk of Segways being considered dangerous?


Not if Segway operators obey the rules of the road for drivers of vehicles. If one accepts the premise that Segways have the maneuverability characteristics of vehicles (e.g. similar to bicycles) when traveling at speeds that are fast enough to make them nearly as useful as bicycles and other vehicles, then a thorough analysis of the causes of crashes for light vehicles leads us to the conclusion that it is usually safer to operate these vehicles on roadways according to the rules of the road than to operate them on sidewalks.

It is true that Segways have enhanced maneuverability when operated at slower, pedestrian speeds, and this may warrant their allowance in some areas that vehicles are normally prohibited if they are operated at slow enough speed. However, if travel speed enhancment is a major feature of the Segweay's appeal, then it will often be operated at speeds where it should be operated according to vehicular rules, and it would usually be safer to do so on the roadway. The Segway is special in that it can be operated either as a vehicle or as a pedestrian, but I believe that its vehicular operation demands drivers' responsibilities and drivers' rights.

As for prohibitions from roadways, remember, the public has the right to use its street system. The government should be given the burden to demonstrate why the Segway *isn't* safe on roadways compared to the other vehicles that are allowed on roadways (e.g. garbage trucks, tractors, construction equipment, bicycles, mopeds, motorcycles, parking enforcement vehicles, etc. that have a wide variety of average speeds and crash absorption characteristics. The best comparison, I believe, is with bicycles, because the Segway technology is capable of traveling at similar speeds, with similar maneuverability to the bicycle.

Despite the fact that many ignorant people don't think roadway bicycling is safe, bicyclists are allowed to use all roads that directly serve destinations, and bicycling has a very low fatality rate - much lower than motorcycling, per hour of exposure, and similar to that of automobile use. There is little harm allowing light vehicles on roadways if all drivers are educated and enforced to operate according to the rules for drivers. But if Segway LLC is trying to spread the idea that light vehicles are unsafe on roadways, and should be prohibited from such, they will face fierce opposition from cyclists, because roadways are the only facilities that go everywhere, and are the safest and most efficient facilities for cycling. Across the world, the right to cycle on streets is a fundamental human rights issue. Just look at the increasing hardships faced by people in China, where the corrupt government is banning bicyclists (the poor majority) from many streets in order to improve convenience for car drivers (the politically and economically empowered minority).

Are the government and Segway LLC prejudiced against the Segway because its wheels are in parallel instead of in series like an electric bicycle? When pulling a child trailer a bicycle is even wider than a Segway. Adult tricycles are street-legal. How sad it is to see Segway LLC beg for its customers to have segregated water fountains and seat in the back of the bus, instead of demanding their full rights as equally entitled road users, like American bicyclist advocates have done.

I believe the only significant design flaw in the Segway related to safety of street use (compared to my commuter bicycle) is the lack of a proper headlight and tail light.

Steve Goodridge
http://www.ncbikeclub.org/documents/Night_Cycling.html

[bicycledriver]

quote:Originally posted by weskifm


Well I rode today and I tried to pay attention to the stopping distances. I must admit I was very wrong about the stopping distances. When I reached what I thought might be max speed with the red key it took at least 10 feet or more to stop. I don't usually ride at max speed unless it is a clear area with nothing to obstruct my progress or endanger me or anyone else or anything else.
I did give it several hard stops and I do think it would be hard to stop it at max speed (12.5 on the i-series) in less than 10 feet. I was attempting the aggresive stops on an asphalt parking lot with a cold but dry surface.


Thank you very much for your honest report. In an earlier post I used the basic motion equations to predict a theoretical minimum braking distance of 8.487 feet from 12.5 miles per hour at .6 Gs. May I ask if the 10 feet or more that you reported included any element of reaction time, or did you start the distance estimation/measurement from the point at which you began braking?

I have done some more research on the subject of reaction time and have found a wide variance in how transportation agencies and regulatory agencies treat the subject. Some agencies, such as the FHWA, include the time that drivers may look away from the road at mirrors, dashboard controls, maps, road sighns, etc. in their estimation of reaction time. This is important for practical purposes such as determining safe following distance or sight distances for real-world traffic situations. The FHWA uses reaction times of over 1.5 seconds as a result. However, this effect may not be what we are looking for when we compare reaction time between vehicles. If we assume the driver is looking in the direction of the threat when it appears, we can concentrate on the time required to recognize the stimulus, which we really cannot remove from a real experiment, and the time required for the body to begin the braking operation. If we wish to compare vehicles this metric would be best. But if we wish to estimate realistic stopping distances for real Segway drivers on real streets and sidewalks, we should consider using the FHWA's methods that incorporate diversion of driver attention.

Steve Goodridge

[GlideMaster]

Hi BD,

I don't know if you've ever ridden a Segway before but you just don't know when you hit 12.5, all you can do is guess that when it starts to rear back you are at the max. I'll have to mark off ten feet next time I glide and see if I can start my stop at a specific point... It's just hard to measure when you're rolling and you say ok start the measuring point now. I mean you're pulling back to stop at the same time you're rolling forward and you're not skidding to a stop, not if you want to stay on your feet. I have did a little skidding in turns on some fine parking lot dirt but that's it.

Hope you understand what I'm trying to say. It's just hard to put into words

[bicycledriver]

weskifm,

I empathize with your difficulty performing an accurate test, especially by yourself. I think it really requires two people - one to just drive, and another to keep track of the start and stop points for the stopping maneuver.

To keep track of the Segway's speed, it might be easiest to drive beside a cyclist with a bike computer. Alternatives are mounting a bike computer on the Segway (the magnet must be mounted on the wheel, and the sensor on fender. Duct tape may hold for a few minutes of testing. Don't forget to measure the wheel circumference and enter this into the computer) or using a handheld radar gun with help from the local police.

The easiest way to get a precise braking distance is to install a light beam interruption detector across the test track (like the doorway beam sensor that Radio Shack sells) and wire the output relay to a light placed 50 feet farther down the path. Drive past the detector at the desired speed while watching the light (not watching the posiiton of the sensor) and begin braking when the light goes on. To measure reaction time it's best if the driver does not know where the sensor is, so the driver cannot anticipate the exact braking location.

Steve Goodridge

[n/a]

Stopping speeds of the Segway are programable as well as other handling characteristics. If it turns out that the current models stop to slowly, perhaps they could be provided with a key that would rectify that problem?

[n/a]

quote:Are the government and Segway LLC prejudiced against the Segway because its wheels are in parallel instead of in series like an electric bicycle? When pulling a child trailer a bicycle is even wider than a Segway. Adult tricycles are street-legal. How sad it is to see Segway LLC beg for its customers to have segregated water fountains and seat in the back of the bus, instead of demanding their full rights as equally entitled road users, like American bicyclist advocates have done.

I believe the only significant design flaw in the Segway related to safety of street use (compared to my commuter bicycle) is the lack of a proper headlight and tail light.


Steve, your arguments sound good to me. It sounds like u may have some valuable info for Segway to listen to. Have u tried to contact them to get a response to your views or to send them a copy of your paper?

[Casey]

quote:To measure reaction time it's best if the driver does not know where the sensor is, so the driver cannot anticipate the exact braking location.


Steve, how do you propose that? A rider would have no way to know when to initiate the stop without markers. If you watch the testing of cars, you will see they have cones set up and pavement marked off in graduated distances. Of course it eliminates reaction time as a factor, but it still shows the ability of the vehicle which I think is the main purpose of a braking test.

Reaction time should be about the same for all vehicles that can't automatically react to driver reflex. That pretty much means all would have the same driver reaction time but Segway. That I think is the main thing that seperates Segway from any other device in total stopping distance.

[GlideMaster]

Hi Lawrence,

The Segway does not stop too slowly by no means. It all depends on your reaction time, speed, surface and ability and desire to really commit to a very hard stop. Oh, and most of all a good insurance policy or medical health plan when you decide to really commit to a really hard max speed stop. Have I ever been down? No! Have I ever been thrown off? No! Have I ever let it get away from me? No! Have I ever tried to make a real hard maximum speed stop. Well if you must know. YES! What happened? Well it was the same reaction I got in my training class from Segway, where you try and roll over a small diameter pipe or a broom stick. The only problem is the result of such a maneuver is magnified ten times. If you try a maneuver like that you had better have on a football helmet, hip pads, knee pads, elbow pads and shoulder pads and an EMT standing by. It was a very very very scary feeling. Please get all of this madness about a full speed stop out of your head. Ride at a reasonable speed, believe me it's sufficient. And I only ride red except to instruct someone, then it's black all the way. I also only ski black or under the chairlift and dI've been skiing 28 years. I've been monoskiing for about the last twelve years.

<center>REMEMBER:
Responsible Riders Ride Segway
and
Segway Riders Ride Responsibly </center>
quote:Originally posted by Lawrence

Stopping speeds of the Segway are programable as well as other handling characteristics. If it tuResponsible Riders Ride Segwayrns out that the current models stop to slowly, perhaps they could be provided with a key that would rectify that problem?

[bicycledriver]

quote:Originally posted by Casey

quote:To measure reaction time it's best if the driver does not know where the sensor is, so the driver cannot anticipate the exact braking location.

Steve, how do you propose that? A rider would have no way to know when to initiate the stop without markers.


If the trip sensor is wired to a light or other visual stimulus source in front of the Segway driver, e.g. farther down the track, the test can measure the driver's response to the visual stimulus without the driver being able to anticipate the stimulus. The trip sensor should be aligned with a cone or other marking to make the distance measurement easy, but *which* cone or marking is attached to the sensor should not be known by the driver in order to avoid driver anticipation.

Steve Goodridge

[bicycledriver]

quote:Originally posted by weskifm


It was a very very very scary feeling. Please get all of this madness about a full speed stop out of your head. Ride at a reasonable speed, believe me it's sufficient.


Wouldn't a reasonable speed sometimes be as high as the maximum speed allowed by law, or by the device? If not, then why is the speed limit (legal or software) that high? I used the 15 mph limit in the North Carolina Segway law for this reason.

Analysis of the habits of utilitarian drivers reveals that they generally travel as fast as they can manage. They will slow down where faster travel is dangerous, but they will generally prefer to go faster and will compromise safety to some degree for convenience, or choose an alternate facility or mode that is more convenient.

Determining a reasonably safe speed for a given environment requires knowing the stopping distance of the vehicle at that speed. Conversely, choosing the right environment for a desired travel speed also requires knowledge of the stopping distance. If the Segway driver wants to travel faster than is safe on a pedestrian facility, the Segway driver will do one of the following:

1. Operate the Segway at unsafe speed on the pedestrian facility
2. Operate the Segway in greater safety on the roadway by vehicular rules(unless this has been prohibited by law as in NC)
3. Switch to another type of vehicle (e.g. electric bike) and use the roadway.

I believe it is important for both safety and accurate prediction of levels of real-world consumer Segway use to analyze the stopping performance of the Segway and its implications for "reasonable speeds" and usefulness of the vehicle.

Steve Goodridge

[Blinky]

Yeah Weskifm, if you could somehow do this 'Test' that would be great. I am very interested in finding out also.

Great idea Steve..

btw: is there anything else he could do that is less scientific?(easier)

[GlideMaster]

Hi Blinky,

Surly you jest or you are in a frolicsome or frivolous mood or am I just the object of ridicule or the butt of a joke? :)
But regardless, I don't work for DEKA and I don't have the desire, time, inclination, equipment or expertise to do these test. I already glide and I don't feel there is any problem with the way the Segway breaks. You have to ride it all the time to know what I mean. The only problem with breaking would be the way a rider rides. You must ride responsibly just like you must drive responsibly; otherwise you know the consequences. :):D[8D][^]

REMEMBER:
Responsible Riders Ride Segway
and
Segway Riders Ride Responsibly



quote:Originally posted by Blinky

Yeah Weskifm, if you could somehow do this 'Test' that would be great. I am very interested in finding out also.

Great idea Steve..

btw: is there anything else he could do that is less scientific?(easier)

[Blinky]

Weskifm writes,
quote:Hi Blinky,

Surly you jest or you are in a frolicsome or frivolous mood or am I just the object of ridicule or the butt of a joke?
But regardless, I don't work for DEKA and I don't have the desire, time, inclination, equipment or expertise to do these test. I already glide and I don't feel there is any problem with the way the Segway breaks. You have to ride it all the time to know what I mean. The only problem with breaking would be the way a rider rides. You must ride responsibly just like you must drive responsibly; otherwise you know the consequences.
Weskifm, I was just looking for a simple yet scientific test that you or maybe someone else out there would be able to do out there. It would be nice to have an easier test for someone who might be willing to do this test.

I am sure you would have been able to handle the first test Steve initially purposed. No doubt about that [^]

[Eddie]

Hi all,
I'd like to point out a few things which seem to have been missed. First, when stopping hard on a Segway the cg (center of gravity) is necessarily behind the cp (contact patch) of the tires. The position of the cg does not move when the stop is completed and therefore the tires must then retreat to a position beneath the cg. This recoil space must be counted as part of the stopping distance even though it may not be critical in all situations.

Second, I would guess that if a rider were to throw their weight back and down by assuming a squatting position then there stands to be a considerable increase in the angle formed between cp-cg and vertical which would take the maneuver closer to the limits of adhesion of the tires.

Finally the analysis on the humantransporter.org website, while an excellent start, does not include certain dynamics which are peculiar to the differing vehicle types. The example of a car for instance does not include the time it takes for the vehicle to begin to brake where the weight transfers to the front tires. During this time the springs and shocks are not fully compressed and the maximum braking ability of the vehicle is not realized. This is one of the reasons why stiffly sprung sports cars stop more quickly than soft sprung luxury rides.

Just my half nibble.:-)

[Blinky]

Eddie, very interesting take on this whole topic. As bicycledriver provided us with his idea earlier in this thread of what the stopping distance would be on a Segway-HT, do you have a formula of your own that you would like to share with us. Any insight would be much appreciated.

We would like to hear from you..

[BruceWright]

What an interesting topic. Steve, you have convinced me that these new segway laws are too restrictive, and that segway riders should be able to use the safest mode of travel, be it sidewalk or roadway, as should bicycle riders, depending on the situation.

I am also interested in Weskifm's report of dangerous situations with rolling over objects like pipes or broomhandles, or coming to a very sudden stop. I'm also interested in Steve Goodridge's analysis that impacting objects below the center of mass of the rider (such as children) would transfer much more velocity to the impacted person, I had not thought of that, although it does make sense.

All of that together makes me of the opinion that Segways travel too fast at their top speed. I know now that I will not use the high-speed key except on open roadway or in an empty lot.

Also, some parts of me wonders if we are missing the point somewhat. Although it's certainly way too early in the development of this device to really entertain this thought: We keep trying to classify this device by the laws of cycles or the laws of pedestrians. I wonder if this is what our grandparents and great-grandparents faced with the automobile. Should it follow the laws for horses, the laws for bicycles, the laws for wagons or the laws for streetcars?

It will take many years and many generations of smart vehicles before a settled state exists, I think. By that time, cars will be more intelligent, and hopefully our civic transportation spaces will be more forgiving.

Bicycles haven't changed much in the last 100 years. I dare not say what a Segway would look like in ten years.

[Blinky]

BruceWright writes,
quote:All of that together makes me of the opinion that Segways travel too fast at their top speed. I know now that I will not use the high-speed key except on open roadway or in an empty lot.
From what it sounds like from other members in this forum, the top speed may be possible on the sidewalks, but from the sound of it your most likely going to take the safe rout(good call) when using the Segway.

note: when you have time you should really read back to the other topics in this site. enjoy!

[Eddie]

Hi Blinky,
quote:Originally posted by Blinky

Eddie, very interesting take on this whole topic. As bicycledriver provided us with his idea earlier in this thread of what the stopping distance would be on a Segway-HT, do you have a formula of your own that you would like to share with us. Any insight would be much appreciated.


I'd simply use Steve's assumptions of .6G deceleration to calculate the angle between vertical and the line formed by the contact patch and the center of gravity. Taking the arctangent of .6 (the ratio of the vectors) gives an angle of about 31 degrees. The hypotenuse of the angle will be the distance between the contact patch and the combined cg of the rider and machine which will depend on the height, weight and position of the rider. For the purpose of this excercise we will assume this distance is about 1.1 meters (43.3 inches). Taking the sine of 31 degrees yeilds .515 which is multiplied by the 1.1 meters to determine the distance the center of gravity is behind the contact patch. The result is .567 meters (22.3 inches). The reason I thought this worth mentioning is that it seems to explain why the calculations may predict an 8 ft. stopping distance that only "feels" like 5 or 6 ft.

As to estimating the reduction in braking capabilities of an automobile while the weight initially transfers to the front wheels would be very difficult to model and highly variable with vehicle and suspension type. It might be worth a thesis paper for a student somewhere and probably a bit much to post here.

[yop]

This 0.6G analysis checks out, but it assumes that the mass of the vehicle is rigidly connected to the wheels. Would it make any difference if this connection were embodied by a spring? Could you convert some of the kinetic energy of the vehicle's motion into potential energy stored in the spring, then release the spring's energy later, after the vehicle has stopped? This could yield a shorter stopping distance. Since the Segway rider is free to absorb energy and forward momentum by leaning back and bending his knees (unlike on a bike or in a car), the spring model might be a better choice.

[hodgepoj]

quote:Originally posted by weskifm

Hi BD,

I'll have to mark off ten feet next time I glide and see if I can start my stop at a specific point... It's just hard to measure when you're rolling and you say ok start the measuring point now. I mean you're pulling back to stop at the same time you're rolling forward and you're not skidding to a stop, not if you want to stay on your feet. I have did a little skidding in turns on some fine parking lot dirt but that's it.



Your message is the first I've read that mentions skidding the Segway wheels when stopping or turning. Is it possible to skid the wheels when stopping or does the machine come equipped with something like an ABS?

Turning a one-axle vehicle requires the driver to either brake the inside wheel or accelerate the outside wheel. It's possible to skid the wheel either way. Which method does the segway use?

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas, Texas 75210

[GlideMaster]

Blinky Blinky Blinky! You and your cabal need to glide (I mean ride). If you did, you would get all of this stopping distance and braking distance stuff out of your head. High speed! There is no high speed as such. When you hit the top speed you will realize you are not going that fast and that you will have time to stop if you are paying attention to what you are doing and are riding like you have some sense. The Segway is very safe if you ride it in a safe manner. It's the rider who can be the problem.

<center>REMEMBER:
Responsible Riders Ride Segway
and
Segway Riders Ride Responsibly

Segway, The Mind Changer</center>

Please read back through some of the older topics because this has been covered in-depth.

quote:Originally posted by Blinky

BruceWright writes,
quote:All of that together makes me of the opinion that Segways travel too fast at their top speed. I know now that I will not use the high-speed key except on open roadway or in an empty lot.
From what it sounds like from other members in this forum, the top speed may be possible on the sidewalks, but from the sound of it your most likely going to take the safe rout(good call) when using the Segway.

note: when you have time you should really read back to the other topics in this site. enjoy!

[GlideMaster]

Hi hodgepoj,

Hodgepoj,it's possible to make just about anything skid if you push it past it's point of adhesion, which depends on whether you're trying to stop on cement side walks, wet cement, fine gritty dirt, grass, waxed floors and on and on and on. Yes I have caused the Segway to skid slightly on a turn on a hard gritty fine dirt parking lot. But I knew I was pushing the envelope and had no problem (being a skier is what helped prevent disaster). I would not recommend anyone try it; by no means. I also tried to see how fast I could stop the Segway listening to some of the request from the brains on this site. Won't do that again. I leaned back and pulled back so hard and fast that it did some type of stutter skid or skip (it's been a while). It was sort of like in the training when they have you role over a small pipe that can roll while the wheels of the Segway roll. Hodgepoj don't ever try any of this. The results could be fatal. I have never fallen or been hurt on a Segway and that's because I practice what I preach. And that is!
<center>REMEMBER:
Responsible Riders Ride Segway
and
Segway Riders Ride Responsibly

Segway, The Mind Changer</center>

quote:Originally posted by hodgepoj

quote:Originally posted by weskifm

Hi BD,


Your message is the first I've read that mentions skidding the Segway wheels when stopping or turning. Is it possible to skid the wheels when stopping or does the machine come equipped with something like an ABS?

Turning a one-axle vehicle requires the driver to either brake the inside wheel or accelerate the outside wheel. It's possible to skid the wheel either way. Which method does the segway use?

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas, Texas 75210

[bicycledriver]

quote:Originally posted by BruceWright
We keep trying to classify this device by the laws of cycles or the laws of pedestrians. I wonder if this is what our grandparents and great-grandparents faced with the automobile. Should it follow the laws for horses, the laws for bicycles, the laws for wagons or the laws for streetcars?


There are essentially two classes of road users: pedestrians and drivers of vehicles. Cyclists are merely a subset of drivers in the traffic laws. I propose that Segwayists should also be classified as drivers under the traffic laws because Segways have the manueverability limitations of vehicles (compared to pedestrians) while also having the greater speed capabilities of vehicles (compared to pedestrians) and they are being marketed based on this speed capability, i.e. the faster they are the more useful and thus more marketable they become.

Segway operators have the same cognitive limitations as other drivers. They have limited peripheral vision, and lack eyes in the backs of their heads. They have a significant response time to stimuli. They often look away from their direct path to look at other things in the streetscape including road signs and other traffic, or to look at vehicle controls or objects they may be handling.

Future Segway operators have similar motivations as other drivers. They want to go places faster than they can by walking. The faster, the better. Otherwise, they would be walking.

Segways are motorized wheeled vehicles with a high center of gravity. The center of gravity and the limitations of rubber tires on real-world surfaces give the Segway limited deceleration and cornering capabilities similar to those of other vehicles.

I believe the combination of the Segway operator's cognitive limitations, motivation to travel quickly, and the maneuverability limitations of Segways favor regulation of Segwayists as drivers of vehicles, because the rules for drivers of vehicles are the safest that anyone has been able to devise for drivers of vehicles. This has been demonstrated to be true for bicycles, automobiles, mopeds, motorcycles and horsedrawn carriages, becasue their drivers are similar and these vehicles have similar maneuverability constraints.

Streetcar drivers follow different rules only because their tracks make it impossible for them to change their lateral position on the roadway. The limitations of fixed tracks on streets are one reason why urban streetcars have been almost completely replaced by buses except in areas with a strong sense of nostalgia. Note that on-road parallel-path streetcar tracks are a significant hazard to cyclists and may cause problems for Segwayists as well.


Steve Goodridge

[Blinky]

Weskifm writes,
quote:Blinky Blinky Blinky! You and your cabal need to glide (I mean ride). If you did, you would get all of this stopping distance and braking distance stuff out of your head. High speed! There is no high speed as such. When you hit the top speed you will realize you are not going that fast and that you will have time to stop if you are paying attention to what you are doing and are riding like you have some sense. The Segway is very safe if you ride it in a safe manner. It's the rider who can be the problem.
I understand. The Segway won't let you go any faster than the top speed you set it to. It will jerk back a little and let you know that you are going 'top speed' and give the user an idea that pushing the Segway's limits won't get you anywhere faster. Not new information.

What I am implying is one might not want to set the Segway on a 'fast key' if on a crowded street. As easy as it probably is to control, why not use some judgement and set your Segway at a 'slower key'.

This is just my opinion of how I think people should use their Segway's on the sidewalk. You are right, "It's the rider who can be the problem." and I don't disagree with you there. I just don't people should chance it in a city like environment.

[GlideMaster]

Blinky Blinky Blinky; it's not the key it's the RIDER. You can go just as slow with the red key as you can with the black key. Once again IT'S NOT THE KEY IT'S THE RIDER. Like you said in this post, "Why not use some Judgement." Yes use your judgement and ride slower where needed. Also, you don't set the speed of the Segway, the factory does.
<center>REMEMBER:
Responsible Riders Ride Segway
and
Segway Riders Ride Responsibly

Segway, The Mind Changer</center>
quote:Originally posted by Blinky

Weskifm writes,
[quote]Blinky Blinky Blinky! You and your cabal need to glide (I mean ride). If you did, you would get all of this stopping distance and braking distance stuff out of your head.
What I am implying is one might not want to set the Segway on a 'fast key' if on a crowded street. As easy as it probably is to control, why not use some judgement and set your Segway at a 'slower key'.

This is just my opinion of how I think people should use their Segway's on the sidewalk. You are right, "It's the rider who can be the problem." and I don't disagree with you there. I just don't people should chance it in a city like environment.

[Blinky]

Lets take this one slow,

Weskifm, You can be the safest rider with the best judgement and still get into an accident. There is no full proof way to ride any vehicle with out the possibility of getting into some kind of accident at any given time.

It is likely if the Segway going at a 'slower key' speed on a busy sidewalk rather than a 'fast key' speed is going to put you in a more likely position to avoid an accident. I don't care how safe of a rider you are, you can still get into an accident. Right?

[Eddie]

quote:Originally posted by Blinky

It is likely if the Segway going at a 'slower key' speed on a busy sidewalk rather than a 'fast key' speed is going to put you in a more likely position to avoid an accident. I don't care how safe of a rider you are, you can still get into an accident. Right?


There are also potential pitfalls of using the 'slow' (black) key. It seems to me that the black key is for training and along with the lower top speed is a slower turning rate which makes the machine less responsive. I am also of the understanding that the yellow key was intended for sidewalks and the red key was for wide open spaces. That said I don't see any problem with running on whatever key is comfortable for you and slowing down when encountering congested areas.

[Casey]

My car only has one ignition key plus a duplicate, and it'll go 140mph according to what I've read. That hardly means I'm going to drive 100mph in a school zone.

The primary speed governor on a Segway is the same one a car has, the driver.

[Blinky]

quote:It seems to me that the black key is for training and along with the lower top speed is a slower turning rate which makes the machine less responsive.
You said it. I didn't say 'slowest key', I just said 'slower'. I think the black key should just be for 'training' or for an owner who is still not comfortable riding a Segway.

[Blinky]

Casey writes,
quote:My car only has one ignition key plus a duplicate, and it'll go 140mph according to what I've read. That hardly means I'm going to drive 100mph in a school zone.

The primary speed governor on a Segway is the same one a car has, the driver.
Alright. You are riding down a busy sidewalk. If there was an incident where someone runs into your back, and your leaning forward on the Segway, are you not better off to have that Segway set at a lower speed to avoid a more potential damaging incident than if it were on a slower key.

This is why I think the slower key should probably be used in a more congested area/sidewalk.

[Eddie]

quote:Originally posted by yop

This 0.6G analysis checks out, but it assumes that the mass of the vehicle is rigidly connected to the wheels. Would it make any difference if this connection were embodied by a spring? Could you convert some of the kinetic energy of the vehicle's motion into potential energy stored in the spring, then release the spring's energy later, after the vehicle has stopped? This could yield a shorter stopping distance. Since the Segway rider is free to absorb energy and forward momentum by leaning back and bending his knees (unlike on a bike or in a car), the spring model might be a better choice.



If you mean that the rider could get as low as possible to reduce the distance which the tires recoil then yes that is possible. It is not possible to reduce the overall stopping distance because the rider is not able to absorb energy or momentum like a spring because the rider is what possesses that energy and must give it up in order to stop. The only mechanism to shed that energy is through either the Segway tires or an object which has been struck.

[Casey]

quote:Alright. If there was an incident where someone runs into your back, and your leaning forward on the Segway, are you not better off to have that Segway set at a lower speed to avoid a more potential damaging incident than if it were on a slower. This is why I think the slower key should probably be used in a more congested area/sidewalk.

You have a valid point. But wouldn't the same thing apply if a semi tailends your car? I understand what you are getting at, but being tailended in a car could also cause you to be forced against the throttle.

[Blinky]

quote:You have a valid point. But wouldn't the same thing apply if a semi tailends your car?
Yes. I suppose it does. We have to remember one thing, the Segway is not going as fast as cars. Initially, Segway owners would most likely not be riding with many other Segway owners on the sidewalks. I am sure a person who gets bumped could take the hit, but not as easily as someone who gets bumped from another on the road. At least we have something to protect us(our newly banged up car :( )

[hodgepoj]

quote:Originally posted by weskifm

Hodgepoj,it's possible to make just about anything skid if you push it past it's point of adhesion, which depends on whether you're trying to stop on cement side walks, wet cement, fine gritty dirt, grass, waxed floors and on and on and on.


Thank you for the physics lesson, weskifm. In my world, your "point of adhesion" is called the "coefficient of static friction."

Any two objects in contact have two coefficients of friction -- the static coefficient when they are not in relative motion and the kinetic coefficient when they are in relative motion.

The coefficient of friction is the ratio between the frictional force parallel to the interface and the perpendicular force that is pushing the two objects together. The static coefficient for any two materials is always greater than the kinetic coefficient for the same two materials. This is another way of saying that it takes a greater force to cause one object to slide over another than it takes to keep it sliding.

The static coefficient for vulcanized rubber on dry concrete is 1.02. On wet concrete it is 0.97. For waxed hickory on dry snow it is 0.03. For steel on steel lubricated by machine oil it is 0.16.

To maintain control of a rubber-tired vehicle, you always want to be in the static friction domain (the wheels are rolling rather than sliding). That's the job of today's anti-skid braking systems.

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas, Texas 75210

[GlideMaster]

Hodgepoj, I was not trying to give a physics lesson. You never know what a persons background might reveal. Some aspects of my job did at one time require a knowledge of objects in motion or to be more on the money Kinetic Friction. A lot of the material had to do with the study of the Force of Friction and Objects at Rest or Static Friction. The coefficient of static friction depends upon the roughness of the surfaces it does not really depend upon the contact surface area of the two surfaces, that is if the two surfaces are not alike surfaces. I was taught that the force of static friction increases to a maximum point, after which the object tires in this case lose traction and begin to move or in some cases slide or skid. Of course a change in the applied force, size of the object and coefficient of friction can all be changed.

Sorry, but this is crazy and has never come to mind when I ride and also has no affect on the way I ride. The only thing that has had any influence on my ability and style of riding has been skiing. Therefore as I leave you, don't try to figure my static region and my kinetic region in relation to the force of friction of my behind as you kick me across the floor. I guess my problem is I'm only interested in the promulgation of the Segway.

<center>REMEMBER:
Responsible Riders Ride Segway
and
Segway Riders Ride Responsibly

Segway, The Mind Changer </center>



quote:Originally posted by hodgepoj

quote:Originally posted by weskifm

Hodgepoj,it's possible to make just about anything skid if you push it past it's point of adhesion, which depends on whether you're trying to stop on cement side walks, wet cement, fine gritty dirt, grass, waxed floors and on and on and on.


Thank you for the physics lesson, weskifm. In my world, your "point of adhesion" is called the "coefficient of static friction."

Any two objects in contact have two coefficients of friction -- the static coefficient when they are not in relative motion and the kinetic coefficient when they are in relative motion.

The coefficient of friction is the ratio between the frictional force parallel to the interface and the perpendicular force that is pushing the two objects together. The static coefficient for any two materials is always greater than the kinetic coefficient for the same two materials. This is another way of saying that it takes a greater force to cause one object to slide over another than it takes to keep it sliding.

The static coefficient for vulcanized rubber on dry concrete is 1.02. On wet concrete it is 0.97. For waxed hickory on dry snow it is 0.03. For steel on steel lubricated by machine oil it is 0.16.

To maintain control of a rubber-tired vehicle, you always want to be in the static friction domain (the wheels are rolling rather than sliding). That's the job of today's anti-skid braking systems.

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas, Texas 75210

[yop]

quote:Originally posted by Eddie

quote:Originally posted by yop

This 0.6G analysis checks out, but it assumes that the mass of the vehicle is rigidly connected to the wheels. Would it make any difference if this connection were embodied by a spring? Could you convert some of the kinetic energy of the vehicle's motion into potential energy stored in the spring, then release the spring's energy later, after the vehicle has stopped? This could yield a shorter stopping distance. Since the Segway rider is free to absorb energy and forward momentum by leaning back and bending his knees (unlike on a bike or in a car), the spring model might be a better choice.



If you mean that the rider could get as low as possible to reduce the distance which the tires recoil then yes that is possible. It is not possible to reduce the overall stopping distance because the rider is not able to absorb energy or momentum like a spring because the rider is what possesses that energy and must give it up in order to stop. The only mechanism to shed that energy is through either the Segway tires or an object which has been struck.


Eddie,

At least part of what you wrote is wrong. If "[t]he only mechanism to shed that energy is through either the Segway tires or an object which has been struck," then regenerative braking wouldn't work.

I'm going to lay out what I was thinking. Maybe you can help me see that I'm missing something.

I was trying to fit bicycledriver's analysis with my personal experience from playing sports. In my experience, athletes on their feet can stop in less distance than what the analysis tells us. Look at Barry Sanders or Lleyton Hewitt. I believe part of the reason for this is the deformability of the human body. Unlike a rigid vehicle like a bicycle or a car, the body can change shape. This shape change allows the stopping distance to be reduced. So bicycledriver's analysis is correct, his calculations give the distance that a vehicle's center of mass will travel before it comes to a stop. But because a pedestrian can bend his knees, he can sort of pull his leading edge backwards, effectively reducing the stopping distance by a foot or two, depending on the length of his legs.

But it's more complicated than that, because in my experience, the strength of the person's legs needs to be factored in as well. The shoes are important of course, but the length of the person's legs and the characteristics of the shoe rubber are not the sole (heh) determinants of stopping distance, that is, it also depends on the stiffness of the spring. I'm not sure how to do this analysis, though. And of course I could be wrong.

[bicycledriver]

quote:Originally posted by hodgepoj

[quote]Originally posted by weskifm


The static coefficient for any two materials is always greater than the kinetic coefficient for the same two materials. This is another way of saying that it takes a greater force to cause one object to slide over another than it takes to keep it sliding.

The static coefficient for vulcanized rubber on dry concrete is 1.02. On wet concrete it is 0.97. For waxed hickory on dry snow it is 0.03. For steel on steel lubricated by machine oil it is 0.16.
....
To maintain control of a rubber-tired vehicle, you always want to be in the static friction domain (the wheels are rolling rather than sliding). That's the job of today's anti-skid braking systems.


We know that there are many real-world surfaces in the streetscape with static coefficients less than 0.6, some lower than 0.4. Examples are wet steel plates/grates, wet thermoplastic/epoxy/painted lines, wet leaves on bricks, sand and gravel. These create skid risks for rubber tires and limit the deceleration rate of the vehicle in Gs.

I believe that the Segway driver suffers more risk during a braking skid situation than does the operator of a car or bike. If a car or bike skids while braking, the operator or ABS system reduces braking until static friction is attained again, and then the braking can be increased again. The stopping distance is increased, but the operator can maintain control of the vehicle. But if a Segway skids while braking, that means that the braking forces on the wheel will no longer balance the torque of the Segway operator's backward lean. This will cause the Segway operator to lean (fall) back even further. This greater lean will require more braking force to bring the rider upright, but if the static coefficient remains low, i.e. the surface does not improve with distance, that braking force will be impossible to attain. The increasing lean angle compounds the problem. This is why a moving pedestrian who slips on ice has great difficulty staying upright unless a foot can reach a surface with greater friction past the ice patch. A fall will occur very quickly with little time to regain static friction.

I therefore suspect that the Segway engineers probably chose to limit the maximum deceleration rate of the Segway to avoid skidding on common wet or sandy surfaces, thus keeping the Segway driver from falling. A coefficient of static friction of 0.5 may be common enough to warrant limiting the maximum level deceleration to 0.5 Gs. A previous post described an attempt at maximum braking at about 0.5 Gs to be rather scary on clean pavement; on wet or sandy surfaces this might result in a fall.

Steve Goodridge

[bicycledriver]

quote:Originally posted by yop
Eddie,
At least part of what you wrote is wrong. If "[t]he only mechanism to shed that energy is through either the Segway tires or an object which has been struck," then regenerative braking wouldn't work.


I think it's easy to confuse the issue of energy transfer with the issue of force and deceleration. The only way the Segway operator can decelerate is to apply a reverse force at the wheel contact point or higher on the body in a collision, as Eddie implied.

Deceleration implies energy absorption. When braking, the reverse force of the wheels due to contact friction can recharge the battery by converting the kinetic energy to potential energy. Alternatively, the energy can transfer to increase the kinetic energy of an object that is struck, or to deform the object that is struck.

It may be possible to absorb some small amount of kinetic energy in the legs and arms when braking. However, the force used to decelerate the entire system must be applied to the tire contact point or to the body/vehicle from a collision or wind resistance. Every action has an equal and opposite reaction - the force vectors must balance out. Thus the tire friction is a potential limiting factor in braking.

Steve Goodridge

[n/a]

quote:I believe that the Segway driver suffers more risk during a braking skid situation than does the operator of a car or bike.

U seem to know your theory bicycledriver. But those who have ridden it give a different impression. They are not all Segway employees.

[Casey]

Loss of traction to a Segway is loss of DS. No DS, no control. I think that is what makes a skid more dangerous on a Segway than other vehicles.

You may recover from a minor short lived skid successfully, but I would think breaking the tires loose on ice or other such slippery surface would be a major problem.

[hodgepoj]

quote:Originally posted by weskifm

Hodgepoj, I was not trying to give a physics lesson. You never know what a persons background might reveal.


You didn't offend me, weskifm, I was just being jocund. A bad habit of mine. In case you didn't see it, I listed my background in a post on Nov 29 2002 at 12:42:28 PM.

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas, Texas 75210

[yop]

quote:Originally posted by bicycledriver
Thus the tire friction is a potential limiting factor in braking.


OK, I think you're right.

I think I now also understand how people on foot are able to stop so much more quickly than cyclists. I think it has to do with the fact that a person on foot bounces up and down as he runs or walks. The result of this bouncing means that their feet strike the ground with more normal force than just their body weight. As a result, they can attain greater braking accelerations without skidding.

A Segway, as a vehicle, will not be able to tap into this effect. Maybe a little if the rider flexes at the knees, but not much.

[bicycledriver]

quote:Originally posted by yop
I think I now also understand how people on foot are able to stop so much more quickly than cyclists. I think it has to do with the fact that a person on foot bounces up and down as he runs or walks. The result of this bouncing means that their feet strike the ground with more normal force than just their body weight. As a result, they can attain greater braking accelerations without skidding.


As a pedestrian bounces up and down, the average force against the ground, over time, must be equal to the weight of the pedestrian. Otherwise the pedestrian would sink into the ground or float into space due to an accumulated vertical momentum.

During a hard impact against the ground, the foot would indeed be able to provide a stronger-than-average braking force. But this effect is offset by the lower-than-average braking force that occurs when the foot is unweighted. If the friction effect is linear with respect to weight, then the average braking force will be the same regardless of modulation of downward pressure.

Pedestrians stop in less distance than some cyclists because pedestrians travel more slowly, or because some cyclists do not know how to use their front brakes, or both.

Steve Goodridge

[BruceWright]

Segway's wheel motors pulse hundreds of times a second. That should make it stop faster than a bike. It's a bike with anti-lock!

The tires are larger, too. In your calculations, did you factor the difference between bike tires (pizza-cutters) and the greater area of road-contact on the Segway?


I took a 5-mile walk at a brisk pace yesterday, (back from dropping my car at the mechanics) wishing I had a Segway all the while. I walked at about twice normal walking speed, and noticed that I could still stand to be moving twice as fast without any safety concerns.

I think that speed would have been perfectly sufficient for added convienience, and been perfectly safe.

Bicycledriver, you keep talking about the fact that people will go as fast as they can with this vehicle, otherwise why choose a vehicle? I have to point out, they have chosen a SLOWER vehicle than the default Car or even a Bicycle. Perhaps slower-paced people will be drawn to this device, or people will use it when they aren't in a hurry.

"Carry More, Travel Further, Be More Productive" doesn't neccesarily mean "Go Faster, Burn Rubber, Get There Sooner."

[yop]

quote:Originally posted by bicycledriver
As a pedestrian bounces up and down, the average force against the ground, over time, must be equal to the weight of the pedestrian. Otherwise the pedestrian would sink into the ground or float into space due to an accumulated vertical momentum.

During a hard impact against the ground, the foot would indeed be able to provide a stronger-than-average braking force. But this effect is offset by the lower-than-average braking force that occurs when the foot is unweighted. If the friction effect is linear with respect to weight, then the average braking force will be the same regardless of modulation of downward pressure.


While running, a person's center of mass is at least a couple of centimeters higher than while stopping, so there's at least a little bit of energy to play with there.

Also, I would expect the friction effect to be non-linear. I know everyone's first physics class says that it is linear... but with real materials in the real world? I would be shocked if the real situation wasn't a lot more complicated.

(For the engineers: I read that rubber shows a non-linear stress-strain relationship. I would not be surprised if it acted non-linearly under friction effect conditions as well.)

[bicycledriver]

There isn't a great difference in friction force between a narrow bike tire and a wide bike tire. The pressure is more concentrated on the narrow tire, for greater stopping power per unit of area, while the wider tire evens out the pressure over a larger surface. Surface imperfections will affect the narrow tire more, but not much. I don't have my copy of _Bicycle Science_ with me to provide numbers right now.

My analysis of stopping conditions for the Segway concluded that lean angle was the probably most important limiting factor on clean, dry pavement. On slippery surfaces the tire friction does become an issue. The variation in surfaces creates a much greater variance in traction than does tire width.

My suspicions about speed behavior are based on observation of typical bicyclists and motorists. Some people operate slowly enough to feel safe, while others operate fast enough to feel a little dangerous. I see no reason to expect Segway drivers to be different. Lots of cyclists travel too fast for conditions around pedestrians; they value speed even though they are operating bicycles instead of automobiles. The same mentality will apply to those who have, for whatever reason, selected a Segway for a particular trip.

Steve Goodridge

[Casey]

quote: There isn't a great difference in friction force between a narrow bike tire and a wide bike tire.

Would you say then that wide tires on high performance cars is a waste of materials and money?

[bicycledriver]

Flat race car tires perform differently than curved bicycle tires due to tread pattern and cornering effects. Wide slicks reduce rolling resistance and distribute heat more evenly to "stick" to the road better. Narrower slicks would erode away faster. On treaded tires, more tread patterns can be employed on a wider tire to increase the probability that some part of the tread will contact a stable, non-slippery surface. These effects are subtle but useful enough to employ on automobiles where weight is less of an issue than on bicycles.

Steve Goodridge

[Carl]

quote:Originally posted by bicycledriver

My suspicions about speed behavior are based on observation of typical bicyclists and motorists. Some people operate slowly enough to feel safe, while others operate fast enough to feel a little dangerous. I see no reason to expect Segway drivers to be different. Lots of cyclists travel too fast for conditions around pedestrians; they value speed even though they are operating bicycles instead of automobiles. The same mentality will apply to those who have, for whatever reason, selected a Segway for a particular trip.


I have a suggestion for why Segways might be safer than bicycles around pedestrians. A sufficiently lazy bicycle rider who is approaching a pedestrian will be tempted to coast past at the same speed, instead of braking and then pedaling to regain speed. A Segway rider may be more willing to slow down since speeding up again does not require the same physical exertion. There's also the fact that (at least non-expert) bicycle riders may have trouble controlling their bicycle at pedestrian speeds; the fact that Segways effectively have no minimum speed should make them safer around pedestrians.

Of course, neither of these issues address concerns about Segways versus automobiles.

[axiotek]

The conversation in this thread is fascinating, I am compelled to weigh in.

Of course the Segway is vehicle. Nothing is 100% safe as seems to be the consensus, but I believe the Segway to be unique. If Segway LLC says the stopping distance is 5 feet from max speed of 12.5 mph then I believe them. I'm not sure if it has been mentioned, (I've never ridden a Segway, placed my order today) but the Segway does not "break" but moves backward absorbing the force via the motors as I understand it, so comparisons to bikes is not valid in that sense because the wheels do not stop in place. If a runner moving at 12 mph can come to a stop in 2-3ft then it seems likely from what I know and what Frank has stated based on his experience that 5 ft is believable with no adverse effects for the rider.

I am an avid cyclist both for pleasure and transportation thousands of Boston urban miles a year. Cyclists and Segwayists are natural allies and I believe in the future Segways will enhance the position of the non-auto vehicle lobby to promote more transit corridors for use by non-auto modes including pedestrians. Bikes are treated very poorly in most urban areas. But for now, as to the question of where Segways belong within the existing transportation infrastructure, they belong on sidewalks.

[CyclistBuddy]

I agree we are all part of the same team, less reliance on cars. The big questions I am reading here concern safety, but i would contend that every mode of transportation is only as safe as its operator. That Segway quote I see, about responsible riders riding Segway, can fit with anything. Its all in how you operate it. The safest machine is still a danger if the operator is dangerous.

I'm a San Fransiscan who does over 9,000 miles a year on my bike, and prefers it to "everything" wherever possible. But I have one question which BicycleRider eluded to early on, how is a healthy private citizen going to use the Segway? Does it have enough advantages over driving or taking public transit? You can easily lock a bike to trees/meters/garbage cans, etc.. You can easily carry a bike up stairs or on buses or cars equipped with bike racks. Most rail lines in the Bay Area allow bikes on trains. This makes it very practical for going anywhere since they are light and some are even collapsable! I am sure the Segway has advantages over the bike, and the bike has advantages over Segway, its just what do you want to do and how the individual sees as the best way to do it. I don't think the segway fills a newly found niche in transportation as Segway LLC describes it "Between walking and driving", but i think with the publicity it can at least get people thinking about not using a car.

So for those of you who have a Segway, how do you intend to use it and how often?

[hodgepoj]

I like your physics explanations, Steve, but I have a couple of nitpicks.

quote:
Deceleration implies energy absorption.


By what? The only requirement for deceleration is an applied force having a component opposite to the velocity. Whatever is applying that force is doing negative work -- that is, it is absorbing the kinetic energy that the slowing object is losing.

quote:
When braking, the reverse force of the wheels due to contact friction can recharge the battery by converting the kinetic energy to potential energy.


The reverse force in braking is applied TO the wheels BY the road. The negative work done by that applied force usually converts kinetic energy into heat energy. Using some of it to recharge the battery converts kinetic energy into electrical energy. The only way for the work done by a braking force to convert kinetic energy into potential energy is to go uphill so that the gravitational force slows you down.

quote:
Every action has an equal and opposite reaction - the force vectors must balance out.


The action force and the reaction force referred to in Newton's 3rd law are always applied to two different objects, not to the same object. If the force vectors are balanced, the object is in equilibrium and its velocity will not change.

Remember that any applied force requires two objects. When object A applies a force to object B, then object B applies an opposite force to object A. If the objects are in equilibrium, these two opposite forces have equal magnitudes. If they are not in equilibrium, then one of the forces is greater than the other and the objects will accelerate.

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas, Texas 75210

[hodgepoj]

quote:Originally posted by Casey

Loss of traction to a Segway is loss of DS. No DS, no control.

What is DS?

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas, Texas 75210

[hodgepoj]

quote:Originally posted by yop


I would expect the friction effect to be non-linear. I know everyone's first physics class says that it is linear... but with real materials in the real world? I would be shocked if the real situation wasn't a lot more complicated.


You lost me on that, yop. In what way would you expect friction to be non-linear? I've taught freshman physics for many years and I can't recall ever associating the word linear with friction.

But you are quite correct in that the real world is always far more complicated than the simplified models we teach in physics. Indeed, that's why we invent the simple models; the real world is too complex to analyze. We leave it for the engineers to solve by their trial and error approach.

quote:
(For the engineers: I read that rubber shows a non-linear stress-strain relationship.)


The stress-strain relationships of ALL materials are non-linear. If they weren't, no material would ever deform or fracture under stress. The linear portion of the stress-strain curve is called the elastic region for that material.

quote:
(I would not be surprised if it acted non-linearly under friction effect conditions as well.)


I still don't know what you mean by this.

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas, Texas 75210

[CyclistBuddy]

Carl, your point about the Segway driver being safer because of being able to slow down and speed up without extra extertion is almost right when compared to cycling alone, all though most of us slow down and call ahead anyway. But I would counter contend that some car drivers and motorcycle riders don't slow down and speed up given similiar situations. As people, we tend to like the smoother ride best, regardless of how we are being transported.

[Eddie]

Hi Paul,
quote:Originally posted by hodgepoj

quote:
When braking, the reverse force of the wheels due to contact friction can recharge the battery by converting the kinetic energy to potential energy.


The reverse force in braking is applied TO the wheels BY the road. The negative work done by that applied force usually converts kinetic energy into heat energy. Using some of it to recharge the battery converts kinetic energy into electrical energy. The only way for the work done by a braking force to convert kinetic energy into potential energy is to go uphill so that the gravitational force slows you down.


Is it not correct to refer to the energy in the batteries as a chemical potential energy or is merely chemical energy the pc* term?

*pc = physics compliant ;)

Oh, DS = dynamic stability

Ed
The puckish one

[hodgepoj]

quote:Originally posted by Eddie


Is it not correct to refer to the energy in the batteries as a chemical potential energy or is merely chemical energy the pc* term?

You are correct, Eddie, but all chemical energy is potential energy in that it is stored and waiting to be transformed into some other form. So calling the energy stored in a battery "chemical potential energy" is redundant.

Most physicists think "gravitational potential energy" when they see the simple term "potential energy."

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas, Texas 75210

[Casey]

quote:Originally posted by hodgepoj

quote:Originally posted by Casey

Loss of traction to a Segway is loss of DS. No DS, no control.

What is DS?

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas, Texas 75210


DS = Dynamic Stabilization

[yop]

quote:Originally posted by CyclistBuddy

Carl, your point about the Segway driver being safer because of being able to slow down and speed up without extra extertion is almost right when compared to cycling alone, all though most of us slow down and call ahead anyway. But I would counter contend that some car drivers and motorcycle riders don't slow down and speed up given similiar situations. As people, we tend to like the smoother ride best, regardless of how we are being transported.


I expect Segway riders to be more courteous than car drivers or motorcycle riders. Whereas a Segway rider is exposed to other people, people in a car or on a motorcycle feel separated from the people around them. A person on a Segway will be more aware of public scrutiny and will therefore act more courteously.* People in cars do all sorts of things that I think will be rare for Segway riders: I bet we don't see too many Segway riders air-guitaring, picking their nose, scratching themselves, etc.



* If they don't, you have my permission to throw a snowball at them. [:p]

[CyclistBuddy]

Yop, thank you for your reply. You are right that people may be more courteous when being exposed to other people. Many cyclists are aware of this and are under the most scrutiny for their actions, since both pedestrians and drivers have beefs against cyclists. Despite this, I have seen many cyclists still running red lights and passing too close to pedestrians on multi use paths without calling out. Its more of a judgement thing than a rider thing.

You may also be correct that we won't see many "segwayists" doing stupid things, but even if there are a few who don't act courteous or alert, it will look bad for all segway riders. The one Segway accident in Atlanta has some people steaming about the Segway already. Thats a lesson I have seen with cycling, a handful of bad cyclists or accidents is all some people need to blame all cyclists. I believe the same will be true of the Segway.

What can you say other than "You can't please everybody.."

[JohnM]

quote:Originally posted by yop
People in cars do all sorts of things that I think will be rare for Segway riders: I bet we don't see too many Segway riders air-guitaring, picking their nose, scratching themselves, etc.


Try and convince me that Segway riders won't use cell phones while moving. ;)


Runnin' with the Big Dogs

[bicycledriver]

quote:Originally posted by axiotek
If Segway LLC says the stopping distance is 5 feet from max speed of 12.5 mph then I believe them.

Where and when did Segway LLC claim that the Segway's stopping distance from 12.5 mph is 5 feet? We have read earlier in this forum that during an actual attempt on a real Segway operating near 12.5 mph the braking distance was over 10 feet.

quote: If a runner moving at 12 mph can come to a stop in 2-3ft

Can a runner moving at 12 mph really stop in 2-3 feet? I don't see how; I need at least that many steps to stop, totaling to over 10 feet.

Steve Goodridge

[bicycledriver]

quote:Originally posted by hodgepoj

I like your physics explanations, Steve, but I have a couple of nitpicks.
quote:
Deceleration implies energy absorption.


By what? The only requirement for deceleration is an applied force having a component opposite to the velocity. Whatever is applying that force is doing negative work -- that is, it is absorbing the kinetic energy that the slowing object is losing.


Right - I should have written that deceleration implies that energy is being transferred or changing form - i.e. from kinetic to potential, or kinetic to chemical storage, etc.

quote:
quote:
When braking, the reverse force of the wheels due to contact friction can recharge the battery by converting the kinetic energy to potential energy.

The reverse force in braking is applied TO the wheels BY the road. The negative work done by that applied force usually converts kinetic energy into heat energy. Using some of it to recharge the battery converts kinetic energy into electrical energy. The only way for the work done by a braking force to convert kinetic energy into potential energy is to go uphill so that the gravitational force slows you down.


Yes, I was thinking of the battery storage as a form of potiential energy. I should have said that regenerative braking converts kinetic energy into elecrical energy which is then converted into chemically stored energy.

It's been a long time since I took physics. I can still get the force vector diagrams right, but I'm out of practice using the right language to describe the laws of motion clearly.

Thanks,
Steve Goodridge

[JohnM]

quote:Originally posted by bicycledriver
quote: If a runner moving at 12 mph can come to a stop in 2-3ft

Can a runner moving at 12 mph really stop in 2-3 feet? I don't see how; I need at least that many steps to stop, totaling to over 10 feet.


This would be very easy to test.
Find a brick wall.
Measure 3 feet out from the wall and draw a line.
Step back about 100 feet and then run at the wall at a brisk pace.
When your foot hits the line, stop.

Any volunteers?

Anyone with a new Segway want to try it with the line moved out to 5 feet?


Runnin' with the Big Dogs

[hodgepoj]

quote:Originally posted by bicycledriver


Where and when did Segway LLC claim that the Segway's stopping distance from 12.5 mph is 5 feet? We have read earlier in this forum that during an actual attempt on a real Segway operating near 12.5 mph the braking distance was over 10 feet.


The uniform deceleration required to stop in 10 feet from 12.5 mph is 33.6 ft/sec^2, slightly greater than 1 g.

quote:
Can a runner moving at 12 mph really stop in 2-3 feet? I don't see how; I need at least that many steps to stop, totaling to over 10 feet.
Steve Goodridge


The uniform deceleration required to stop in 2 or 3 feet from 12.5 mph is 84 to 56 ft/sec^2, between 2 and 3 g's.

Dr. Paul O. Johnson
Senior Exhibit Developer
The Science Place
Dallas, Texas 75210

[bicycledriver]

quote:Originally posted by hodgepoj
The uniform deceleration required to stop in 10 feet from 12.5 mph is 33.6 ft/sec^2, slightly greater than 1 g.


That would require a lean angle of about 45 degrees and tire friction better than that of rubber tires on most real-world travel surfaces. But we also know that the deceleration cannot be uniform; some time is required to start and stop the deceleration, which would require a maximum deceleration even higher to accomplish in the same distance.

quote:
The uniform deceleration required to stop in 2 or 3 feet from 12.5 mph is 84 to 56 ft/sec^2, between 2 and 3 g's.


We know that this is impossible. I think people spend so little if any time running in urban traffic that they don't appreciate the effect that this speed has on their stopping distance as pedestrians. Braking distance increases with the square of velocity. The short stopping distances of walking pedestrians is due to their slow speed; promotion of a device for the purpose of traveling much faster than most pedestrians will result in stopping distances much, much longer than that of most pedestrians.

The slower the Segway goes, the less useful it is to able-bodied citizens. The more useful it is, the longer its stopping distance. This is one of the characteristics of vehicles used for personal transportation in the real world. In order to predict the maximum usefulness of the Segway, one must consequently predict operational dynamics that belong on roadways instead of sidewalks. This is as much for the safety and convenience of the Segway operator as for anyone else.

Steve Goodridge

[pt]

quote:Originally posted by bicycledriver...The slower the Segway goes, the less useful it is to able-bodied citizens. The more useful it is, the longer its stopping distance. This is one of the characteristics of vehicles used for personal transportation in the real world. In order to predict the maximum usefulness of the Segway, one must consequently predict operational dynamics that belong on roadways instead of sidewalks. This is as much for the safety and convenience of the Segway operator as for anyone else.

for me, the segway is as useful as when it's slow or fast, it depends on the situation and what tasks i'm performing.

would you say that speed always needs to = usefulness? what about traveling at pedestrian speeds but carrying loads. what about commuting on a segway and have different legs of a commute, some areas you're on open road, some sidewalk, you use both at the appropriate speed.

for the most part 90% of my daily commute on the ht is on roads, sidewalks are only transitions.

cheers,
pt

http://www.bookofseg.com

[bicycledriver]

quote:Originally posted by pt
would you say that speed always needs to = usefulness? what about traveling at pedestrian speeds but carrying loads.


I do believe that transportation of cargo in pedestrian spaces will be one of the most useful applications of the Segway. Mail workers, EMTs, and other service workers will likely find the Segway handy.

But when considering just transportation of humans at increased convenience, the supposed intended purpose of the HT, speed increases usefulness. The area of destinations that can be reached within a given amount of time increases in proportion to the square of the travel speed. People adjust their travel behavior in order to maximize the selection of destinations they can access and to reduce the time they must spend reaching a given destination.

quote:
what about commuting on a segway and have different legs of a commute, some areas you're on open road, some sidewalk, you use both at the appropriate speed....for the most part 90% of my daily commute on the ht is on roads, sidewalks are only transitions.


The longer the trip, the more important speed is to reduce the travel time. Since higher speed is more dangerous and less practical on sidewalks, use of the roadway portion of the travel corridor is important as you point out.

So here is my question: Does your state law allow operation of a Segway on the roadway? Or does the state law mandate that you stay on the sidewalk whenever a sidewalk is present, or to travel against traffic where no sidewalk exists? Does the Segway law prohibit travel based on the posted *maximum* speed limit of the roadway?

This is what is so ridiculous about the anti-vehicular Segway legislation: it requires operation that limits the usefulness of the Segway by requiring slow travel on sidewalks wherever present, requires dangerous operation in ways known to increase crash and injury rates, and/or prohibits travel by Segway outright on a road that is otherwise legal for use by pedestrians and cyclists.

Steve Goodridge

[JohnM]

quote:Originally posted by bicycledriver

[quote]Originally posted by pt
So here is my question: Does your state law allow operation of a Segway on the roadway? Or does the state law mandate that you stay on the sidewalk whenever a sidewalk is present, or to travel against traffic where no sidewalk exists? Does the Segway law prohibit travel based on the posted *maximum* speed limit of the roadway?


Pt is lucky to be living in Washington which defines the Segway as both a vehicle (with exemptions from licensing, registration, financial responsibilty, etc) and as a pedestrian.
http://www.leg.wa.gov/pub/billinfo/2001-02/Senate/6300-6324/6316_sl_04032002.txt


Runnin' with the Big Dogs

[bicycledriver]

quote:Originally posted by JohnM
Pt is lucky to be living in Washington which defines the Segway as both a vehicle (with exemptions from licensing, registration, financial responsibilty, etc) and as a pedestrian.
http://www.leg.wa.gov/pub/billinfo/2001-02/Senate/6300-6324/6316_sl_04032002.txt


Interesting: in Washington a legally defined EPAMD can go up to 20 mph, but any municipality can prohibit EPAMD use on any road posted with a maximum speed limit above 25 mph. Many cities have citywide speed limits of 30 or 35 mph. In other words, an EPAMD user must check the local ordinances in every single town in which one travels, and the allowance for roadway use may change from street to street. This type of local baloney is what cyclists have organized to successfully oppose for generations in order to protect their travel rights.

The Washington law also says the EPAMD driver must yield to all human-powered traffic at all times, regardless of the positions and paths of travelers, rather than according to the ordinary rules of the road. In other words, if the EPAMD driver is moving down the street at 15 mph, and a cyclist rides out of a driveway directly in front of him, the EPAMD driver can be cited for failure to yield.

I certainly wouldn't accept such anti-Segwayist legislation if I were a Segwayist.

Steve Goodridge

[Poindexter]

quote:

The Washington law also says the EPAMD driver must yield to all human-powered traffic at all times, regardless of the positions and paths of travelers, rather than according to the ordinary rules of the road. In other words, if the EPAMD driver is moving down the street at 15 mph, and a cyclist rides out of a driveway directly in front of him, the EPAMD driver can be cited for failure to yield.
Steve Goodridge



Of course this is not true. First, the bicyclist has to stop before crossing a sidewalk or entering the roadway (not like a car is required to do).

It is the cyclist that would be at fault if he failed to yield when entering the roadway. If the Segway is on the roadway, at the time, the Segway has all the rights of a motorist.

If you look closer I think you'll see the non-motorized yeild requirement is for sidewalk/bikepath stituations.

[bicycledriver]

quote:Originally posted by Poindexter

[quote]
If you look closer I think you'll see the non-motorized yeild requirement is for sidewalk/bikepath stituations.


Thanks; that would make more sense. The URL listed did not provide context for some of the additions.

However, I do note that sidewalks and bike paths tend to be awful places for vehicle/vehicle interaction because operators often ignore the principles and rules that would apply on roadways. I don't think placing a higher burden on EPAMD users than bicycle users is very useful here, especially for interactions between cyclists and Segwayists.

Steve Goodridge

[ftropea]

On the plus side, pt can ride his Segway on the sidewalks :)

I've been carefully following the very persuasive case that's been presented by Mr. Goodridge and JohnM. However, I'm still not convinced Segwayists should "team up" with cyclists at this point. There should be differentiation between the two (Segways and Bicycles) until we see how Segways fare on sidewalks. That's the responsibility currently charged to Segway early adopters - show the world that the idea works, for example.

If and when that happens, I wouldn't mind Segwayists pushing for expanded road access - but I hope it's because they'll want to expand their accessibility options, and not because of anti-Segway legislation, such as we've seen out of SF, to ban them.

I admit there are clearly shared interests here. However, while I appreciate Mr. Goodridge's concerns about the Segwayist's rights when it comes to road access and the like, the sentiment seems half-hearted when you realize where it's coming from. To be more specific, Mr. Goodridge did admit he thought Segway LLC's lobbying efforts were screwing up some state traffic laws, and that he perceives this as being bad or "not so harmless to cyclists."

While I appreciate that cyclists have spent decades fighting for their access rights, I'm not convinced that Segwayist's use of sidewalks is detrimental to a cyclist's existence or use of the roads.

That said, I'm still open to new ideas as they're presented here.

Regards,

Frank A. Tropea

[JohnM]

quote:Originally posted by ftropea

On the plus side, pt can ride his Segway on the sidewalks :)


Plus side? PT said:
quote:
..for the most part 90% of my daily commute on the ht is on roads, sidewalks are only transitions.


The status of the Segway on the roads is an issue that needs to be addressed now. How Segways fare on the sidewalks seems to be a secondary issue to riders like PT, who are pushing this discussion beyond the theoretical and into the real world.

Runnin' with the Big Dogs

[ftropea]

No, it's not an issue now. That's why Segway LLC isn't lobbying for road access or to have the Segway-HT classified as a vehicle. A person who utilizes a Segway becomes an empowered pedestrian. They don't become "Segway Drivers" - although I know that's how a few of you see it. That's a term created in this thread in order to illustrate a point. Does the term "Segway Driver" originate from any written law, ordinance or media - either online or in print?

I accept that cyclists such as you and Mr. Goodridge consider yourselves to be "bicycle drivers", and that you don't view Segway-HTs, or Segwayist's interests, to be all that different from bicycles or cyclist's interests - but I think Segwayists would disagree with you. Segway LLC certainly doesn't agree with you.

Pt may understand the shared interests, but perhaps even he wouldn't agree to be labeled a "Segway Driver" if that meant he had to follow pre-existing bicycle laws. Everyone knows who has the stronger support base. There are millions of cyclists and perhaps less than a few thousand Segway owners.

That's why I don't want to see that issue addressed now. Segwayists have a right to prove their sidewalk worthiness. Cyclists had their chance and the rest is history.

Regards,

Frank A. Tropea

[bicycledriver]

quote:Originally posted by ftropea


I admit there are clearly shared interests here. However, while I appreciate Mr. Goodridge's concerns about the Segwayist's rights when it comes to road access and the like, the sentiment seems half-hearted when you realize where it's coming from. To be more specific, Mr. Goodridge did admit he thought Segway LLC's lobbying efforts were screwing up some state traffic laws, and that he perceives this as being bad or "not so harmless to cyclists."

While I appreciate that cyclists have spent decades fighting for their access rights, I'm not convinced that Segwayist's use of sidewalks is detrimental to a cyclist's existence or use of the roads.


The poem By Pastor Niemoller went:
"First they came for the Jews
and I did not speak out
because I was not a Jew.

Then they came for the Communists
and I did not speak out
because I was not a Communist.

Then they came for the trade unionists
and I did not speak out
because I was not a trade unionist.

Then they came for me
and there was no one left to speak out for me."

Advocates for drivers of light vehicles need to understand that the push to ban light vehicles from roadways is a prejudiced attempt by highway establishment to place the interests of selfish motorists above the interests of all other traffic. The highway establishment, including both the road building lobby and militant motorist groups, have been trying to rid the highways of bicyclists for generations. They failed to do so because their agenda was based on taboo, superstition, and prejudice. They tried to say that the attempted prohibitions were for the safety of good of cyclists, but not one shred of scientific evidence supported this claim. Rather, scientific investigation into the causes of injuries to cyclists demonstrated the opposite, that roadway prohibitions increased injuries to cyclists and made bicycle transportation inconvenient or impossible. Bicyclists who acted and were treated as drivers of vehicles, with equal rights to roadways, fared best.

Given a lack of scientific support, the anti-cycling groups relied on taboo and prejudice to make roadway cycling seem socially unacceptable, as though an engine and high speed made one a more worthy user of public streets. They also spread superstition that roadway cycling is dangerous, and attempted to miseducate the public about proper cycling. Cycling groups, in turn, banded together to create their own educational campaigns to teach safe and effective bicycle driving and to oppose the bad laws and bad education put forth by the government. Meanwhile, the anti-motoring environmentalists saw fear of motor vehicles as an opportunity to try to sabatoge the performance of the roadway system and reduce motoring by taking road space away from motor vehicles and reallocate it for pedestrians and pedestrians-on-wheels in the form of discriminatory, segregationist bike lane stripes and glorified sidewalks. Unfortunately, this did even more harm to competent cyclists, because those things that are good for competent bicycle drivers tend to also be good for motorists, which conflicted with the anti-motorists' cause.

The anti-segwayist legislation that limits Segway users' access to roadways is a result of the systematic societal superstitions and discrimination against drivers of light vehicles. Even the Segway drivers themselves have been convinced that their banishment from the superior transportation facilities is for their own good, and they lobby not for equal rights, but to officially assign superior status to automobile operators. Roadway access is not likely to come later, instead, the attempts of Segway LLC to spread and reinforce the taboo against the operation of light vehicles on roadways is nailing the lid on the coffin of equal access for many motorized scooter owners, and threatens the legacy of equal access of drivers of bicycles - the most popular vehicle in the world.

If I do not stand up for the rights of those whom I see oppressed in ways that I might be oppressed, no one will be left stand up for me.

Regards,
Steven Goodridge

[JohnM]

quote:Originally posted by ftropea

No, it's not an issue now. That's why Segway LLC isn't lobbying for road access or to have the Segway-HT classified as a vehicle. A person who utilizes a Segway becomes an empowered pedestrian. They don't become "Segway Drivers" - although I know that's how a few of you see it. That's a term created in this thread in order to illustrate a point. Does the term "Segway Driver" originate from any written law, ordinance or media - either online or in print?

I accept that cyclists such as you and Mr. Goodridge consider yourselves to be "bicycle drivers", and that you don't view Segway-HTs, or Segwayist's interests, to be all that different from
bicycles or cyclist's interests - but I think Segwayists would disagree with you. Segway LLC certainly doesn't agree with you.

Pt may understand the shared interests, but perhaps even he wouldn't agree to be labeled a "Segway Driver" if that meant he had to follow pre-existing bicycle laws. Everyone knows who has the stronger support base. There are millions of cyclists and perhaps less than a few thousand Segway owners.

That's why I don't want to see that issue addressed now. Segwayists have a right to prove their sidewalk worthiness. Cyclists had their chance and the rest is history.


You're talking theoretical Frank. PT owns a Segway and intends to ride it in the street. The lobbyists never took into account that the real world is connected by roadways. Sidewalks don't go everywhere.

And here's the result of that 'history' in PT's home state of Washington:
quote:
RCW 46.61.755
Traffic laws apply to persons riding bicycles.
(1) Every person riding a bicycle upon a roadway shall be granted all of the rights and shall be subject to all of the duties applicable to the driver of a vehicle by this chapter, except as to special regulations in RCW 46.61.750 through 46.61.780 and except as to those provisions of this chapter which by their nature can have no application.

(2) Every person riding a bicycle upon a sidewalk or crosswalk must be granted all of the rights and is subject to all of the duties applicable to a pedestrian by this chapter.


Cyclists had their chance, seized it and got laws that protect their rights and define their duties. The pre-existing 'bicycle laws' that you want nothing to do with are the same rules of the road that apply to all vehicles. Beats me why a Segway owner wouldn't want the same thing.


Runnin' with the Big Dogs

[ftropea]

JohnM,

I'm not saying there aren't shared interests or that Segwayists wouldn't want some road access. I'm only saying Segwayists not only want sidewalk access, but also pedestrian status, since they're nothing more than "empowered pedestrians" and not "Segway drivers." They just want access to the places people can go. Some differences being the ability to move faster and carry more than your average pedestrian.

You know.. the cake and the ability to eat it too.

Regards,

Frank A. Tropea

[axiotek]

quote:

Advocates for drivers of light vehicles need to understand that the push to ban light vehicles from roadways is a prejudiced attempt by highway establishment to place the interests of selfish motorists above the interests of all other traffic. They failed to do so because their agenda was based on taboo, superstition, and prejudice.


I agree with the first part, but have they failed? I think not, the efforts of the auto-lobby have been most successfull at transforming the landscape for their own purposes to the exclusion of almost everyone else.

quote:

Meanwhile, the anti-motoring environmentalists saw fear of motor vehicles as an opportunity to try to sabatoge the performance of the roadway system and reduce motoring by taking road space away from motor vehicles and reallocate it for pedestrians and pedestrians-on-wheels in the form of discriminatory, segregationist bike lane stripes and glorified sidewalks. Unfortunately, this did even more harm to competent cyclists, because those things that are good for competent bicycle drivers tend to also be good for motorists, which conflicted with the anti-motorists' cause.


This is one of the reasons why, and I say this as an urban cyclist in one of the worst cities in the country for biking, that I am extremely bothered by the rails-to-trails program. Unfortunately, those advocates are unwitting dupes of the auto-lobby. It is all about ROW or right of way. Once the ROW is surrendered, it is extremely difficult to take back.

quote:

Even the Segway drivers themselves have been convinced that their banishment from the superior transportation facilities is for their own good, and they lobby not for equal rights, but to officially assign superior status to automobile operators.

Roadway access is not likely to come later, instead, the attempts of Segway LLC to spread and reinforce the taboo against the operation of light vehicles on roadways is nailing the lid on the coffin of equal access for many motorized scooter owners, and threatens the legacy of equal access of drivers of bicycles - the most popular vehicle in the world.


This is where I disagree. Roads are not necessarily superior. It is the ROW that is important. Although quite impressive, the Segway lobbing effort is not yet positioned to begin taking over the streets, yet they need legal protection. Street access will come eventually as the lobbying grows especially in dense urban areas and this redesign of streets will be to the benefit of all modes. Just look at the resume of Segway LLC's CEO.

[JohnM]

Frank,
Go back to my last post and read RCW 46.61.755. Read all of it, even the part about sidewalks and pedestrians.
Bicyclists in Washington have their cake and eat it too. Sure you don't want a piece? You are so concerned with being new and unique and a part of the 'vision' that you're refusing a seat at the table.

Runnin' with the Big Dogs

[JohnM]

Axiotek,
Have you read any of the laws that the Segway lobbyists had passed? Road use is in nearly all the 30+ laws passed to date. But for the most part its unsafe use with limited rights and poorly defined responsibilities. Segway LLC got the sidewalk use they wanted but created a dangerous situation regarding street use.


ps
Segway LLC's CEO drives a Hummer and lives an a neighborhood with no sidewalks. He's out of touch with his own vision.

Runnin' with the Big Dogs

[axiotek]

quote:Originally posted by bicycledriver
People adjust their travel behavior in order to maximize the selection of destinations they can access and to reduce the time they must spend reaching a given destination.


This is overly simplistic. There are numerous factors that go into the decision as to mode of travel. Trip time is not everything. Productivity is also very important (e.g. working on a train) and as you stated proximity. But convenience, safety, comfort, access to choice can all trump trip time.

I can see a Segwayer travel home from work simutaneously running three errands before an auto user could even find a parking spot.

If the above were true, no one would drive to a destination in a congested area (excluding carring a load) under a mile, because one could often walk faster.

[CyclistBuddy]

Quote:
No, it's not an issue now. That's why Segway LLC isn't lobbying for road access

But they are laboring VERY hard for sidewalk use only without any real usage patterns or consulting from the users. Shouldn't the Segway users be the ones asking for the legistlation in the first place? How can Segway LLC know your concerns before you are even using it?
Without current legislation your concerns can be addressed without having previous decisions blocking progress. In CA, they allowed them on sidewalks only and completely forbid them from the streets. That was a huge mistake. Try to lobby for street use now in CA that they have already been disallowed. I almost think Segway LLC is actually laboring to not allow you on streets.

[axiotek]

quote:Originally posted by JohnM

Axiotek,
Have you read any of the laws that the Segway lobbyists had passed? Road use is in nearly all the 30+ laws passed to date. But for the most part its unsafe use with limited rights and poorly defined responsibilities. Segway LLC got the sidewalk use they wanted but created a dangerous situation regarding street use.


ps
Segway LLC's CEO drives a Hummer and lives an a neighborhood with no sidewalks. He's out of touch with his own vision.

Runnin' with the Big Dogs


I have read some of the laws. As a matter of fact, I am contacting reps to try and get some status in MA, yet pending. I am very familiar with this law as a copy is right in front of me at this moment. It is the same as the WA statute.

I don't think the situation regarding the legal status of street use is "dangerous." Perhaps I'm missing something. We all know that laws are not always enforced as written. Cyclists often move on to the sidewalk as a shortcut or to avoid danger. Cops here have arrested cyclists for riding on the street. The law and the reality of the street is much different. But I agree, it is nice to have the law when you finally end up in court.

I only mention CEO because he is a former auto man. He may not share the exact vision, but he knows the market. pt is a good example of the millions of second cars that could say bye bye. That is the market they have their eye on. Slowly but surely...

[ftropea]

I'm mostly concerned about being found guilty by association - in other words, Segwayists being grouped with Cyclists.

Regards,

Frank A. Tropea

[bicycledriver]

quote:Originally posted by axiotek
This is where I disagree. Roads are not necessarily superior. It is the ROW that is important.


I think that roads are superior for vehicle use because of (1) they provide access to all important destinations (or at least nearby parking), (2) they are smooth with few fixed obstacles, and (3) the rules for traffic negotiation are well defined for safety and efficiency. If a better system existed for vehicle travel, drivers would have demanded it. Those issues that do involve friction between drivers of vehicles with different speed capabilities can be mitigated by thoughtful roadway design (e.g. passing facilities), education, and enforcement.

quote:
Although quite impressive, the Segway lobbing effort is not yet positioned to begin taking over the streets, yet they need legal protection. Street access will come eventually as the lobbying grows especially in dense urban areas and this redesign of streets will be to the benefit of all modes. Just look at the resume of Segway LLC's CEO.


I took a look at Dean Kamen's Hummer parked outside the Bedford restaurant where he ate downstairs from my sister's wedding rehearsal dinner this summer. I also looked at the surrounding streets, and noticed that things have not changed much for the better in New Hampshire since I grew up there in Londonderry. There are very few sidewalks despite the increasing traffic on many of the suburban roads. (The lack of sidwalks in the New Hampshire suburbs is one of the reasons why I learned to operate a bicycle as a lawful vehicle driver.) Pedestrian and pedestrian-on-wheels travel is declining in most areas of the United States, and vehicle use is increasing. This means that we are unlikely to see much reallocation of space away from vehicles toward pedestrians. The one segment of bicycle use that is increasing in the USA - recreational cycling - tends to involve higher speeds than that of low-income plainclothes cyclists. These aerobic cyclists are even more likely to benefit from operating on roadways as drivers of vehicles than at slower speeds on pedestrian facilities.

I do strongly promote the improvment of pedestrian facilities for pedestrians. As the volume of vehicular traffic increases, it is important to design our roads properly to protect the safe passage of pedestrians. However, I don't see this as helping light vehicle operators except where those vehicle operators temporarily operate by pedestrian rules under rare circumstances when it provides an advantage, such as when performing a pedestrian-style left turn at a very wide road.

Steve Goodridge

[pt]

quote:Originally posted by JohnMHave you read any of the laws that the Segway lobbyists had passed? Road use is in nearly all the 30+ laws passed to date. But for the most part its unsafe use with limited rights and poorly defined responsibilities. Segway LLC got the sidewalk use they wanted but created a dangerous situation regarding street use. ps Segway LLC's CEO drives a Hummer and lives an a neighborhood with no sidewalks. He's out of touch with his own vision.

that's kinda mean, and i don't think it's true at all.

i assume you meant dean kamen, he's the chairman and does drive a hummer:
http://www.segway.com/aboutus/executive_management_team.html

john, have you met dean, have you spent time with him? i have and i know many people that have, i'll be able to talk about that soon, but i can say this now-- the broad statements your making just aren't accurate, he certainly "eats his own dog food"...and the vision is quite strong.

i also drive a bmw, but we got rid of our other car-- if you watched our travel needs for a week (or dean's you'd see why).

as far as "unsafe" goes, compared to what? i commute everyday to work on one, dangerous is the last thing i would say about my commute now that i'm segwaying to and from home. things aren't always black and white, in wa where i am, there are many forms of transportation going on, and at the end of the day it's about personal responsibility and common sense within the guidelines that do the best job they can.

just some thought, everyone needs to lighten up a bit. these are amazing times, really.

cheers,
pt

http://www.bookofseg.com

[bicycledriver]

quote:Originally posted by axiotek
I don't think the situation regarding the legal status of street use is "dangerous." Perhaps I'm missing something.


You may be missing the fact than in many states the anti-Segwayist law requires the Segway operator to travel *against* traffic when on the roadway. This is the absolute most dangerous way to operate a vehicle on a roadway, as has been demonstrated by years of bicycle collisions, and everyone should know this. The anti-Segwayist law also prohibits travel on most of the useful roads because of their MAXIMUM posted speed limit - a dangerous precedent for drivers of alternative vehicles. Some potential Segway owners will not be able to leave their driveways legally via Segway.

quote:
Cops here have arrested cyclists for riding on the street.


Does anyone still think I am paranoid?

Steve Goodridge

[JohnM]

quote:Originally posted by axiotek

I don't think the situation regarding the legal status of street use is "dangerous." Perhaps I'm missing something.


Perhaps what your missing is that most of the laws treat Segways only as pedestrians and grant them only the limited right of pedestrians when in the street. This forces Segways onto left shoulder riding against traffic. Studies of bike accidents show this to be a dangerous use of the roadway. If the law you're looking at grants Segways vehiclular status like the WA law, great.

You say you're "an urban cyclist in one of the worst cities in the
country for biking". Where in MA? I used to ride from Woburn into Boston's Back Bay for several years. Loved every minute of it.



Runnin' with the Big Dogs

[axiotek]

Sorry, I was referring to Muller (president) former President of Subaru of America, Inc, not Dean Kamen, CEO.

[JohnM]

quote:Originally posted by ftropea

I'm mostly concerned about being found guilty by association - in other words, Segwayists being grouped with Cyclists.


No one will ever do that. Segwayists don't sweat.

Runnin' with the Big Dogs

[axiotek]

Yes, Boston. I didn't say I don't love cycling. Would'nt do it if I didn't, but Boston has often been rated as one of the worst cities in which to bike and we get little respect. I would never ride a Segway against traffic despite what the law says. The MA law like WA would allow street access and I think this is nice flexiblity, but mandates lights and other safety measures. I think bikes are legaly supposed to have lights at night, but few do, that is what I mean about the intent of the law and its on-street application.

[bicycledriver]

quote:Originally posted by axiotek

The MA law like WA would allow street access and I think this is nice flexiblity, but mandates lights and other safety measures. I think bikes are legaly supposed to have lights at night, but few do, that is what I mean about the intent of the law and its on-street application.


Bicycles operated at night are required by law to be equipped with a white headlamp in front and a red rear reflector or lamp. The front headlamp is required for visibility to other road users who are on a path intersecting with the cyclist's at a right angle. Since the other road user's headlamp does not illuminate the cyclist approaching from the side, that road user may be unable to see the cyclist and proceed forward into a collision. The bicycle's headlamp allows the cyclist to be detected before the other vehicle's headlamp can illuminate the cyclist, at which point it would be too late. Note that this problem exists anywhere that traffic paths cross regardless of whether the cyclist operates on the roadway or on the sidewalk.

The rear reflector is needed for visibility to overtaking traffic. This is of greatest importance to road cyclists but can affect sidewalk cyclists at intersections as well. Note that the rear reflector should be large and bright for good visibility to faster traffic approacing from a distance. I use two large automotive reflectors. A red light is also helpful for visibility to traffic approaching from an angle and for visibility at longer distances. I use a very bright LED blinky on all of my bikes.

Unfortunately, there is a great deal of ignorance about legal, safe and effective bicycle lighting in the US. Bicycle equipment manufacture is not regulated by the USDOT, but instead by the Consumer Products Safety Commission, which knows next to nothing about traffic science or the causes of car-bike collisions. The front reflectors sold on bicycles are not an adequate substitute for the legally required headlight, and the tiny rear reflector mandated by the CPSC for bikes is quite dim. As a result, cycling at night without legal or effective nighttime lighting equipment is one of the leading causes of urban bicycle fatalities.

Steve Goodridge
http://www.humantransport.org/bicycledriving/gallery/page5.html

[JohnM]

Honest to God, I'm not making this up.....
I spotted a Segway on my drive into Manchester this evening.( No bike today. Spent the day up in Lebanon, 75 miles north.) I was sitting at a red light on the west end of the Amoskeag Bridge, north Manchester, when I see a single headlight coming across the bridge on the opposite side of the street. It's a Segway, in the outter westbound lane, not on the sidewalk, moving with the flow of traffic. The NH law, 1st Segway law in the country, says that as a pedestrian the EPAMD should be on the adjacent sidewalk. He isn't. Had there been no sidewalk, the pedestrian EPAMD should be on the left side of the road, moving against traffic. He isn't. Nope, he's out there in traffic behaving as a vehicle! This fellow is smart enough to know that the law written by lobbyists in the employment of his boss make no sense in the real world and he is having none of it. The light goes green as he approaches the intersection and he zips through, helmeted head held high.
Jeez, I love a healthy dose of reality after the theoretical discussions that go on here.

Runnin' with the Big Dogs

[Blinky]

If I had a quarter for every time I see an adult riding on the sidewalks of New York City I would be able to buy a Segway at no out of pocket expense. What is to stop them?

It is not that I don't think that Segway rider was wrong, because he/she is wrong, but you are going to see that kind of behavior in all kinds of places. The biggest question would be "How do we enforce the Segway laws?" Will it be that big of a deal to arrest or fine that rider?

Any suggestions?

[bicycledriver]

quote:Originally posted by Blinky

If I had a quarter for every time I see an adult riding on the sidewalks of New York City I would be able to buy a Segway at no out of pocket expense. What is to stop them?


Police are free to ticket cyclists who operate on sidewalks in cities where sidewalk cycling is illegal. Sidewalk cycling prohibitions don't prevent cyclists from getting to their destinations, and the roadway is safer for the cyclist anyway.

quote:
It is not that I don't think that Segway rider was wrong, because he/she is wrong, but you are going to see that kind of behavior in all kinds of places. The biggest question would be "How do we enforce the Segway laws?" Will it be that big of a deal to arrest or fine that rider?

Any suggestions?


The Segway rider was doing the smarter, safer thing. It's the law that is wrong - very wrong. One should lobby to change a bad law, of course, but if obedience of a law creates a serious danger to oneself or others, one should also disobey it. This is a crime of necessity, but in terms of discrimination against Segway drivers is is also a healthy form of civil disobedience. Any prosecution of such competent individuals will help draw attention to the problems with the Segway legislation.

I applaud the actions of this Segway driver!

Regards,
Steve Goodridge

[Blinky]

Its great to have you Steve, good point! :D

To applaud a person doing something wrong to bring attention to a law that should be changed is not the way to do it.

This is a crime of necessity, but in terms of discrimination against Segway drivers is is also a healthy form of civil disobedience.

Even a crime that was even more petty than this one would not serve Segway's interest. I think the formal way of doing things, going through the local politicians would be the way to go.

This is not saying your idea is radical in any way ;)

[JohnM]

quote:Originally posted by Blinky


It is not that I don't think that Segway rider was wrong, because he/she is wrong, but you are going to see that kind of behavior in all kinds of places. The biggest question would be "How do we enforce the Segway laws?" Will it be that big of a deal to arrest or fine that rider?


Illegal maybe, wrong no way. He was operating in a safe manner following vehicular rules that have been in practice for 100 years. The bigger question is, "Why enforce a law that was rushed into place by lobbyists without thought to safe EPAMD operation?"

A big deal? Would you really want to see the headline in the Union Leader, "DEKA/Segway employee arrested for illegal scootering"?

Runnin' with the Big Dogs

[Blinky]

The only thing I would mind is the 'Scootering'

[ftropea]

Mr. Goodridge: You forgot to add a smiley. Surely you don't encourage people to break the law.

JohnM: "Theoretical Discussions" ? ..and this is coming from someone with no Segway riding experience? Remember, even much of Mr. Goodridge's Segway study is "theoretical" yet we don't discount it.

Also, good point about how much of a "big deal" is is. I'm sure if this guy got a ticket, and he/she was a Segway employee, there would be a few red faces over in Manchester. I think of all people, Segway employees must follow the laws to the letter. And then some.



Regards,

Frank A. Tropea

[BruceWright]

As far as my safety goes, I will operate the Segway the most safe way possible for myself and other users of the road, and if I get a ticket, so be it. I'll fight an unsafe law in court if I can't get satisfaction at the ballot box.

A ticket vs. a broken leg (or worse?). It's no contest for me.

[ftropea]

BruceWright..

Do you drive your car with the same philosophy - in a manner of your choosing, regardless of existing road laws? Just let me know where you drive.. I don't want to take a chance ;)

While we're at it, why don't we all go out and drive our cars on the sidewalk?

If it's late and people are safe in their homes, it's a heck of a way to beat the traffic!

And no, I'm not comparing operating a Segway to driving a car - just pointing out that we shouldn't be so quick to arbitrarily ignore the laws.

Regards,

Frank A. Tropea

[BruceWright]

If I thought it was safer, and I could prove it in court, yes I might drive different than the law stated. Judges can spot bad laws, too.

To knowingly risk lives with my automobile because I was following the letter of the law would be at least negligent and at worse criminal. That's why we have courts, of course, to keep unjust laws off the books. In order to challenge an unjust law, one must have standing. In order to have standing, one must be cited for breaking it.

If the courts decide I'm wrong, and I lose my appeals, then I pay my fine and stop driving or riding the Segway until I deem it to be safe.

I'm not talking about arbitrarily ignoring laws, I'm talking about operating a vehicle safely when the laws put me and other people at risk. Either that, or I will not ride at all.

[BruceWright]

One example of where I would break an auto law, Frank.

I might run a red light to push a stalled car with a child strapped in a baby seat from the path of an oncoming train.

Yes, I will break the law, in my own judgement and as I deem fit, I will run that red light.

The need for life and death safety supercedes any traffic infraction.

[JohnM]

quote:Originally posted by pt
as far as "unsafe" goes, compared to what? i commute everyday to work on one, dangerous is the last thing i would say about my commute now that i'm segwaying to and from home. things aren't always black and white, in wa where i am, there are many forms of transportation going on, and at the end of the day it's about personal responsibility and common sense within the guidelines that do the best job they can.


First, I believe here is nothing inherently unsafe about the Segway. At least it's no less safe than other forms of low speed transportation.

My safety comparison conserns the 30+ laws passed this year. Your Washington law is safer than my New Hampshire law. The New Jersey law is safer than the California law. The laws are unequal in the status assigned to the Segway when the sidewalk ends. And sidewalks do end. Any law that would force a Segway rider to act like a pedestrian when in the street is, in my opinion, an unsafe law. Any law that would force a Segway on to a crowded sidewalk when the road might be a better choice is an unsafe law. A good law recognizes the duality of the Segway, i.e., both its sidewalk and street potential. You are already taking advantage of your states flexible law and riding within the law where you feel safest, sidewalk and street. Not everyone is so lucky.


Runnin' with the Big Dogs

[JohnM]

quote:Originally posted by ftropea
And no, I'm not comparing operating a Segway to driving a car - just pointing out that we shouldn't be so quick to arbitrarily ignore the laws.


And we shouldn't be so quick to pass arbitrary laws. All the Segway laws give it a fair shot at the sidewalk, but apply wildly different rights and responsibilities on the street. Very arbitrary. What I witnessed tonight was illegal here in New Hampshire, but would be perfectly legal in Washington.

You should compare operating a Segway in the street to driving a car. What makes our traffic rules work is that they are applied equally to all vehicles; cars, trucks, motorcycles, bikes and horse-drawn buggies. Everybody plays by the same rules, therefor you can safely anticipate what the other guy is going to do. The Segway on the Amoskeag Bridge was following the same rules as everyone else. There was nothing arbitrary about that. And it was cool to see him fit in so well.

Runnin' with the Big Dogs

[pt]

quote:Originally posted by JohnM...would be perfectly legal in Washington.

man, i'm really really really glad i moved to seattle.

cheers,
pt

http://www.bookofseg.com

[bicycledriver]

quote:Originally posted by ftropea

Mr. Goodridge: You forgot to add a smiley. Surely you don't encourage people to break the law.


If obeying the law is likely to get the person killed or seriously injured, then certainly I recommend breaking the law. I also recommend lobbying to change the law, but a such an extremely bad law should not be obeyed. The cost of being prosecuted is less than the hazard of obedience.

I have successfully lobbied politically to change anti-cycling laws here in Cary, NC. The local laws conflicted with state traffic law and were simply unsafe and discriminatory. I certainly didn't obey them while waiting for them to be repealed. See
http://www.humantransport.org/bicycledriving/cyclinglaws.htm

Steven Goodridge (Sitting in the front of the bus or eating at the lunch counter, so arrest me!)

[bicycledriver]

quote:Originally posted by ftropea

BruceWright..

Do you drive your car with the same philosophy - in a manner of your choosing, regardless of existing road laws? Just let me know where you drive.. I don't want to take a chance ;)

While we're at it, why don't we all go out and drive our cars on the sidewalk?

If it's late and people are safe in their homes, it's a heck of a way to beat the traffic!

And no, I'm not comparing operating a Segway to driving a car - just pointing out that we shouldn't be so quick to arbitrarily ignore the laws.


Frank,

After over a hundred years of experience, the traffic laws for drivers of vehicles have evolved to be very safe and effective. Virtually all of the situations where breaking the traffic law for drivers of vehicles could be safer than obeying it have been eliminated by improving the law or modifying the roadway environment. This was done because drivers demanded it.

There are a few catch-22 situations where safer actions may violate the letter of the law - for example, due to sight obstructions a driver wishing to pull out of a driveway may not be able to see traffic on the roadway until his vehicle is blocking the sidewalk. Yet the traffic laws prohibit blocking the sidewalk. The driver cannot simply charge into the roadway without verifying that the coast is clear, and must stop if it is not. Thus it is impossible for the driver to operate safely without breaking the law by necessity. This is where the police and courts forgive crimes of necessity. (Drivers blocking sidewalks is also one of the reasons that Segway drivers and bicycle drivers will get annoyed trying to travel on sidewalks instead of on the streets).

The traffic law prohibits dangerous actions that are not specifically prohibited elsewhere. It's illegal to hurt people with your vehicle. e.g.:
quote:NC § 20-140. Reckless driving.

(a) Any person who drives any vehicle upon a highway or any public vehicular area carelessly and heedlessly in willful or wanton disregard of the rights or safety of others shall be guilty of reckless driving. (b) Any person who drives any vehicle upon a highway or any public vehicular area without due caution and circumspection and at a speed or in a manner so as to endanger or be likely to endanger any person or property shall be guilty of reckless driving.

The traffic law has been carefully written to minimize conflicts between safe operation and the letter of the law. But the basic principle of avoiding danger is always given more weight by the courts than compliance with a specific provision written by imperfect lawmakers in an imperfect world.

What we are discussing in this forum are special laws that violate all of the principles that went into the creation of the existing laws for drivers of vehicles. These special, misguided Segway-specific laws are based on superstition, taboo and prejudice instead of science, fairness, and safety. That is why it is ethical to suggest that they be broken.

Steven Goodridge

[Blinky]

Where would society be today without any traffic laws? I am sure most laws do us pedestrians some good. Are you just referring to the laws that Segway legislation defy?

[bicycledriver]

quote:Originally posted by Blinky

Where would society be today without any traffic laws? I am sure most laws do us pedestrians some good. Are you just referring to the laws that Segway legislation defy?


I defend the laws that apply to drivers of vehicles as being based on scientific theories and empirically confirmed principles of crash prevention and fairness among road users. The utility of these laws at protecting the safe passage of citizens to their destinations is what makes them good laws.

I deride the anti-Segwayist Segway-specific laws that conflict with the established laws for drivers of vehicles because these Segway laws threaten the safe passage of citizens to their destinations. The anti-vehicular Segway laws are not based on good science or ethics, and will eventually be abolished or modified one way or another. Better sooner, from the loud protests of those affected by them, than later, after people get hurt or are denied access to their destinations.

I have modified my earlier post to make it clearer as to which laws I am attacking.

Steve Goodridge

[axiotek]

bicycledriver et. al.

Have you ever heard of woonerfs. It is a type of shared street design promoted by the Dutch. Check out the following sites.

"Hamilton-Baillie, a British architect and a student of how modes of travel produce changes in urban culture, showed how city streets across Europe are being redesigned into "woonerfs," a Dutch term loosely translated as "living yard." " (from the first site)

http://www.cvrti.utah.edu/~macleod/bike/mbac/woonerfs.html

http://6690.adahost.com/sharedstreets.html

How's that for speed and access?

[bicycledriver]

quote:Originally posted by axiotek

bicycledriver et. al.

Have you ever heard of woonerfs. It is a type of shared street design promoted by the Dutch. Check out the following sites.

"Hamilton-Baillie, a British architect and a student of how modes of travel produce changes in urban culture, showed how city streets across Europe are being redesigned into "woonerfs," a Dutch term loosely translated as "living yard." " (from the first site)

http://www.cvrti.utah.edu/~macleod/bike/mbac/woonerfs.html

http://6690.adahost.com/sharedstreets.html

How's that for speed and access?


The Cary P&Z board on which I serve has approved a couple of multi-family residential projects that included woonerf concepts in the design of the local access drives. Such designs work well for short streets and neighborhood areas where pedestrian traffic should generally have priority over vehicle traffic. Vehicle traffic on such streets is greatly inconvenienced compared to streets with greater segregation between pedestrians and vehicles. Consequently, such street designs are inappropriate for facilities on which drivers are expected to travel longer distances and will desire to travel at higher speeds.

As a cyclist, I sometimes travel on urban or neighborhood streets that may have a significant amount of pedestrian traffic in the roadway and low vehicle traffic. I find that I have a higher rate of near-collisions on such roads due to pedestrians doing unpredictable things. This is exacerbated by the fact that as a cyclist I am small and quiet; pedestrians do not see me coming or underestimate my speed. As a result I must often reduce my speed by 25-75%. I would surely have collided with a teen skateboarder, two children, and a dog walker on low-traffic roads in the last six months had I not slowed to less than 50% of my cruising speed when I found pedestrians in the roadway. These folks did not see me and moved in front of me unpredictably at the last moment but were saved by my reduced speed and my prediction that they might do the worst possible thing. Cars are wider and must go even slower in woonerf-like environments, but are louder and more visible, resulting in fewer of the near-collisions that I have experienced.

In summary, a woonerf provides good access and allows vehicular travel at very slow speeds, but is inconvenient for longer vehicle trips.

Steve Goodridge (who as a first-time tourist in New Orleans accidentally turned onto Bourbon Street in a rental car - a legal but highly ineffective decision.)