Solved problem. There are actually moving sidewalks that accelerate you as they go, see https://www.treehugger.com/urban-design/accel-moving-sidewalk-thyssenkr

Solved problem. There are actually moving sidewalks that accelerate you as they go, see https://www.treehugger.com/urban-design/accel-moving-sidewalk-thyssenkrupp-dream-come-true.html https://www.treehugger.com/urban-design/accel-moving-sidewal... Somewhere I saw a prototype of a multi-belt system as well. You get on a shorter one at normal speed, and you can either transition to one moving twice as fast as the first, or you can step off completely. The speed difference from stationary to slow is the same as from slow to fast - you just accelerate by shifting belts.