Thursday, December 20, 2007

When your bus breaks down, 11-8-2006

I wrote most of this on the bus more than a year ago, but had not previously published it anywhere.


My bus was late again today. Not just a few minutes late, as is often the case, but more than fifteen minutes late. Under normal circumstances, when I can't see a bus coming, or when I know I have extra time, I will often walk up the bus line to the next stop, opposite to my direction of travel, to get a little extra exercise and also to increase the chance that I'll get a seat. Today I walked 3/4 of a mile where I found my bus, stranded, with a crowd milling around outside it. A motorized scooter and its operator were sitting on the bus' wheelchair lift, which had broken down partway up. The bus driver had called for assistance. Several more minutes passed. The next bus came along, and though it was already full, it accepted a dozen more passengers, to the point where it was so overfull that a woman at the back door screamed to prevent a man from boarding behind her.

A Metro supervisor arrived in a maintenance van, opened up a panel on the side of the bus, and began working on the lift. The hydraulics remained locked up, but a manual crank was available, and after a few minutes the supervisor was able to flip down the barrier behind the scooter, so that it could be backed off the lift. Then he stowed the ramp and the remaining 30 passengers boarded, including a large group of students traveling together. The next bus would be along any minute, half an hour after the ailing bus should have left this stop, but I boarded it anyway. It would be unable to attempt to pick up any more wheelchair passengers, of course.

What equipment or procedures could have been in place to prevent an occurrence like this one? For starters, the likelihood of a lift breakdown would have been greatly reduced in a low-floor bus, which King County Metro has been already been phasing in (though not on my route, yet). In a low-floor bus, a ramp is all that's needed to bridge the several inches in height difference between the curb and the bus floor -- the wheelchair lift is almost unnecessary. This hastens boarding under all conditions as well as reducing the chance for a breakdown like this one. Some other transit technologies like light rail and Personal Rapid Transit (PRT) have an even better solution: a vehicle floor at the same level as the station platform, though a raised curb at every bus stop -- a boarding platform of sorts -- would accomplish the same thing. However, on buses a ramp or lift would still be necessary, since buses cannot reliably stop close enough to the curb to ensure that the ramp wouldn't be needed. PRT would have the additional benefit of being able to carry a larger number of wheelchairs and scooters (and bicycles) -- one per vehicle, with a vehicle going by every few seconds -- than trains or buses could, as space is limited on buses and trains for wheelchairs, bicycles, or motorized scooters -- buses are generally limited to two or three per vehicle.

A PRT network would have the additional benefit for all passengers of not requiring transfers, and of nonstop travel, but these benefits would be particularly great for disabled passengers, for whom every transfer -- and every delay -- has a disproportionate impact.

The European Commission has now committed major funding to PRT development, with systems being built in London and planned in Rome, with test tracks being built all over the world. When the mobility benefits of PRT are considered alongside its tremendous energy efficiency (2-4 times more energy efficient than buses, trains, or cars), it's a wonder that PRT systems aren't being more carefully considered in the Puget Sound region, or in all but a few other locations in the United States.

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