I agree. Great idea. It actually exists, but rarely in the states. I noticed it in Japan.

A weight sensor could tell whether somebody was on it and keep it running until all passengers are off.

We actually also have this kind of escalators in China. Very good idea.

I've seen some moving walkways with this feature. There is a light beam that gets broken to start the walkway moving.

These escalators are all over scandinavia.

This technology is also applied in Germany. Great idea!

You realize that in the USA at least, everyone would conclude the escalator was broken unless they came close enough to activate it. It should be obvious what a showstopper that is - few businesses would be keen on turning a foolproof transportation system into a frequently confusing one.

An escalator is never broken. When they quit moving they are called "stairs".

It would take a bit of education to teach people an apparently immobile escalator is still in service.

Hey, people push buttons to call elevators (lifts). They are capable of pusing buttons on escalators.

No buttons here in Helsinki. They just start when you get on.

Strange, in Belgium we also have those escalators for a long time, not everywhere though.