Some of you may remember that, last August, I posted an article about moving sidewalks, a transportation technology that enjoyed a brief spurt of enthusiasm around the beginning of the twentieth century, but never really caught on in a big way.
The Slate site has been running a “Nimble Cities” project, in which it invited readers to submit and vote on ideas for improving urban transportation. Some of the ideas were fairly standard (which is not to say they were bad), like bicycle highways, or more flexible working hours. One submission that caught my eye, though, was for moving sidewalks. The author of the article, Tom Vanderbilt, reviews some of the history of the technology, from its introduction at Chicago’s 1893 Columbian Exposition. For a variety of reasons, the idea never really caught on for large-scale applications.
There are of course moving walkways in places like airport terminals, but it’s not clear that they really help all that much. According to the article, the American Society of Mechanical Engineers mandates a maximum speed of 4.57 meters per second. or 15 feet per second. I have been on quite a few of these walkways, and have never encountered one running at anything like that speed; the article says that speeds around 1-2 feet per second are more typical. The walkways are also generally short, and there is also the problem that Jerry Seinfeld identified:
… the people who get onto the moving walkway and just stand there. Like it’s a ride. Excuse me, there’s no animated pirates or bears along the way here.
There are still proposals and experiments being developed, but nothing seems likely to come to a boil anytime soon. The article cites one recent experiment that I was unaware of: the Trottoir Roulant Rapide that was installed in the Montparnasse Metro station in Paris. (Paris, by the way, has some really enormous Metro stations, so the experiment had some practical potential, as anyone who has walked through the Les Halles station can attest.) It apparently had design and maintenance problems, and was taken out of service.
The idea is still intriguing; perhaps someone will eventually hit on the right combination of characteristics to make it a success.