The Arthur C Clarke solution is "anisotropic matter" - walkways that are firm in the vertical direction but can flow in the horizontal axes, so that the same moving way can start slowly, accelerate to a high speed, and decelerate at the other end, all without any transitions.

Although, if we're making arguments about accessibility, I'm sure a more prosaic solution could be found that was no less accessible than just walking normally. But in any case, the usual approach is to have a scalable system for the 99% case, and then to provide an alternative that doesn't scale for the 1% who can't use the scalable solution - chairlifts etc.