Comment by bobthepanda

6 days ago

People have tried faster moving walkways many times. The problem is getting humans on and off such a system safely in a way that is easy to maintain.

In practice, everyday transportation systems need to accommodate a wide variety of users safely, like a toddler, or a commuter holding a cup of coffee, or a grandmother with a walker.

> People have tried faster moving walkways many times. The problem is getting humans on and off such a system safely in a way that is easy to maintain.

Right. You can build it, but not make it ADA-compliant. One subway station in France tried a 4km/h moving sidewalk, but the accident rate was too high.

The Paris system was really two trains on parallel tracks. Here's the mechanism.[1] Same concept as buses and trains where there are turntable sections between the cars. Powered by motors on the tracks. Possibly the first application of distributed power, with many motors pulling together in a controlled way.

Disney's PeopleMover, also powered by track motors and friction, can be thought of as a descendant. Disney had elaborate plans for little cars on tracks for EPCOT, but that never worked out.

[1] https://www.worldfairs.info/forum/viewtopic.php?f=10&t=125-l...

  • Pearson airport in Toronto has ones that accelerate up to a fast speed. People who can’t use them can either walk beside them or hire a small electric golf cart. There is no reason to ban them just because a small portion of the population can’t use them.

    • Not sure but I think I read a while ago that they were removed due to unreliability (it's a while since I've been there myself).

      It was very clever how they did the acceleration/deceleration - the "tiles" of the walkway fit together in such a way that each could slide on top of the next one, and at the two ends the tiles would gradually slide closer together (decelerating) or further apart (accelerating).

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  • it is worth noting that we have transportation systems where you get into a slow moving vehicle that then speeds up. the cable car is a lot safer than a faster moving sidewalk because you can just get inside and sit down securely.

    of course, it takes up a lot more space and costs a lot more money.

    • That's been tried. Never Stop Railway, 1924.[1] The drive system is a variable pitch screw between the rails. Large screw pitch between stations for fast travel, much tighter pitch in stations for very slow movement along the platform.

      Never tried again with that kind of drive, although there are park rides where the loading platform moves. This requires safety devices and staff to prevent people jams at the end of the platform.

      [1] https://www.youtube.com/watch?v=EX_MlWL7YKM

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    • And you can only hop on/hop off a cable car at predetermined locations. To keep average speed high, those tend to be spaced relatively far apart.

      I’m not sure about the “takes a lot more space”, and I definitely doubt about the “costs a lot more money”. Using outdoor escalators as proxies, I suspect outdoor moving sidewalks will need lots and lots of maintenance. If you want to have some guarantee of service you’ll also need multiple sidewalks side-by-side.

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