Escalators that detect footfall?

 

I’m watching a modern mainland Chinese drama on YouTube that was aired on Chinese TV in 2015.  There’s a scene involving taking the restaurant chef to the hospital for his skin allergy.  I see that the escalators carry on moving even when there’s no one around.

    This makes me think:  why not design them (escalators anywhere, not just in hospitals and not just in China) so that they only start moving when people approach or step onto the lowest step, rather like ceiling lights that go off after x seconds when there’s no movement in the room?

    This should save some energy (and therefore bills as well, so it’s economical, not just ecological).  I think there’s an escalator at a London Underground station (Liverpool Street?) that already does this:  I thought it’d only started to move as I stepped onto it a fortnight ago when I was there.

    Smoke detectors work on the same principle (springing into action when there's something alien or different in the air, in this case “smoke”), and they’ve been around for a while.

    Automatic doors that slide open or revolving doors that start to go round (in shops, supermarkets, hotels and office blocks, just to name four off the top of my head) at the approach of a human being have been around for decades, so why not escalators in the 21st century?

   

    My nearest Tube station, Manor House on the Piccadilly line in Zone 2 in north London, does not consistently have that many people throughout the day.

    The London Underground Tube system is so vast there must be loads of other stations (outside central London / Zone 1, or even Zone 2) that have very slack footfall stretches outside peak time.

    I was once in conference with someone in a classroom at the university, in the late 90s.  As we were just sitting there, discussing the text for translation, not moving at all, the lights would go off after a certain duration.  We had to start waving our arms about to set off the movement detectors.

    So, why not escalators in the 21st century when even AI (artificial intelligence) is so advanced?

(2025)