Saturday, May 23, 2009

34> Access for the Disabled

Bengt Gustafsson ( ) in his comments on my most recent post reminded me of a subject that has been long troubling me; Access for the disabled. I think I read somewhere that in one of Ed Anderson’s many attempts to get a project going, he was rebuffed when he tried to offer a special vehicle for the disabled and had to do a complete redesign after his idea of requiring wheelchair bound travelers to sit sideways was ruled out. Apparently every serious design is now bigger, heavier and more expensive than would ordinarily be the case. The track must also be heavier, meaning more support posts, and heavier vehicles take longer to stop, as well as consuming more power to operate. In other words, ADA (Americans with Disabilities Act) compliancy for a uniform fleet will hugely and negatively affect the cost of the whole network. Getting appropriations for infrastructure is already a challenge that restricts the scope of such projects. ADA compliancy, if they are unwilling to budge on these issues, can only mean leaving more areas unserved. Don’t these people see what they’re doing? A fully implemented PRT network would open new worlds for anyone who cannot drive, especially the elderly and disabled. Waiting a minute longer for a special vehicle would be a very small price to pay.
Unfortunately the language of the ADA is in fundamental opposition to efficient PRT. PRT should take advantage of the fact that the average occupancy of a vehicle is only 1.2 persons, by optimizing for the common case and hence saving an enormous amount of energy and infrastructure costs. The ADA seeks to absolutely equalize the perceived experience for the disabled to the standard experience- but since the disabled require additional resources, this in turn forces us to expend additional, unnecessary resources on each and every rider. While an identical experience for the disabled is a nice ideal, the conservation of diminishing world resources and global warming are far more pressing.
So how about this; the vehicles come in two or more sizes. I know that seems like a lot of gratuitous headache and overhead, but I can think of no other option. Rather than have a special vehicle for the disabled (which has been deemed unacceptable) I would suggest segregating the fleet into two weight classes, with the lighter being only for a couple of passengers with luggage, for example, and passengers with any more than that would call for the heavier model. This would include anyone with need for such a vehicle, not just the disabled, such as families. The control software would dial the headway way up for the heavier vehicles to minimize the weight factor, which would not adversely affect system performance much because of the proportionally low ridership of the vehicles.
These heavier vehicles should naturally cost more, but the handicapped can always be given a discount, I bet that kind of discrimination gets little challenge.


cmfseattle said...

The disabled are your allies; among groups that don't ID as PRT advocates, they've often been the most supportive.

Ed Anderson initially suggested wheelchairs ride sideways because he thought they'd be safer that way. At the time, his vehicle design had a separate door on either side. The vehicle was the same size; the seat was changed so that one side could be raised (like the back seat in some hatchback cars).

You know, you really should spend more time researching PRT history. Ed Anderson designed the Taxi2000 guideway in 1981. Raytheon's engineers thought they could do it better (those who have the gold make the rules). Raytheon called their version PRT2000.

akauppi said...

I share your view that making compromises to serve disabled should not render the service itself more costly for everyone else.

But I have another point on the solution. Thinking wheelchairs is thinking now and gone. There's a lot of advancement on artificial legs and sometimes they actually outrun (heh) traditional ones. In other words, I think disabled people of the future won't be that disabled, after all. They'll be mechanically assisted, and they'll be perfectly capable to sit down on a bench and stand up from there. They won't need to lug around troublesome wheelchairs, either.

In this environment, the whole ADA discussion would seem rather stupid, though I understand it can be used to torpedo down PRT systems. If done so, the interest is not on the disabled people, it's on the torpedoing itself.

Another, current approach I have is. So what if PRTs are for all the "regular" people. Use of them will free more space on the ground for other traffic, including that of the disabled people.

Mr_Grant said...

In the US separate-but-equal is by definition unequal and therefore discriminatory. I imagine the concept also exists under European law.

I also can't think of any government that will formulate current public policy based on what technology innovations might occur on an unknown timeline.

Dan said...

Dan The Blogger Responds-
Thanks for your comments, all. Yes, I’m history challenged. This is about the third time I’ve been called on the Anderson/Raytheon connection. I should stick to designing. I’m still in the woods, and research of any kind is pretty tough. As per the laws and solutions, while it is true that the “disabled” is hardly a term that applies to many these days, and this “enabling” trend will certainly continue, the laws aren’t going anywhere, and neither are the lawyers. And democratic governments can only do what is “politically correct” for the times. (I am certainly not anti-disabled, just frustrated with a system that would hamstring meaningful progress for all) Therefore in lieu of any better solution, I offer my dual capacity strategy, since it seems to me that the needs of the disabled, in terms of design, are not materially different from those with weight issues or larger groups.

The real question, from my perspective, is this; Is even legal to spec a system based on the premise that a computer will space vehicles far enough apart to change the structural requirements of a bridge or truss? If it is mandatory that the structure must support bumper to bumper, loaded to capacity, heaviest-case vehicles, (plus some additional safety margin) then it is a mute point. We might as well just resign ourselves to “super-sized” PRT, and all that that implies.

akauppi said...

I see the situation as this:

There is existing policies, which have accumulated in the last 100 years or so, based on that era's presumptions (economical growth is a must, climate is bigger than man).

Then there's the reality we face today and the 100 years to come (economy can grow but use of resources cannot; we are definately part of the climate).

Many current established institutions and proceedings simply won't fit in the new world. If we want to have one. They need to be relaxed and new ways reinvented instead. We simply must reinvent societies, that's it.

Ecological footprint will become imperative at _some_ point, and at that point it will seem funny we've put so much emphasis on following old traditions (read: laws). I design for that era.

As a personal background, because it maybe helps put the above in context:

I'm brought up in Finland in the era when it was a "wellfare state". One of the ideals seemed to be that no-one must excel. This wasn't stated so, of course, but as "equality". Still it meant the same. The school system has really struggled with this, because people simply _aren't_ equal. Some are brighter than others, and that is no bad thing. The not-so-bright kids excelled in other areas of life and we all knew it.

Today the situation is different and we've already changed remarkably. To embrace the future, we need to be yet more agile, innovative and bold.

Bengt Gustafsson said...

On the technical side I would like to point out that the weight and size increase of the guideway due to a size increase and some weight increase of vehicles is not that big. Even with zero weight vehicles the guideway does have to have a certain weight to support itself with spans of, say, 80 feet. The extra guideway weight added to support an extra 100 kg or so needed for the ADA compliance adds only a few kgs per guideway meter. Also, if vehicles get longer, weight per meter may actually go down.

Finally, there are more uses for a larger vehicle than ADA-compliance. For examples see our new cabin design at:

Anonymous said...

It didn't seem to me that having larger vehicles for everyone seemed to be that big an issue. Especially since it's nice to have enough room for larger parties, shopping bags or luggage, and bicycles.

Perhaps its better to have mostly large vehicles with the option to order a one-person vhicle, rather than the other way around, with the one-person vehicles being offered at a discount. That way wheelchair people wouldn't have to wait and those who are traveling alone and don't need all that space would be able to travel cheaper if they're willing to wait an extra minute or so. Also, it would be much easier to store the smaller vehicles at or near stations for call-up than it would be to do so for larger vehicles.