Why not? Don't they use moving floors on airports already? Yes, but they also have non-moving floors, and they also have -- in the US, at least -- a small flee

Why not? Don't they use moving floors on airports already? Yes, but they also have non-moving floors, and they also have -- in the US, at least -- a small fleet of carts, driven by airport staff, that can carry people who have difficulty walking. Any moving-walkway mass-transit system would have to include accessible alternatives.