Just heard an amazing anecdote ... during that 10'th anniversary for 9/11. It was from a blind guy who had to descend the stairs in the WTC from a long way up. He had a guide dog with him, and just had to go slow. He spent most of the time trying to be reassuring to his pooch, while throngs of panicky people bypassed him on the stairs. But he still made it out OK.

But you are right - this is a major problem for people in wheelchairs. Maybe unsolvable.

Pete2