A drunk person, who is not fit to operate an escalator, might push the button and endanger everybody.

It may be safer to risk the occasional mangled human limb, or crushed to death mother of a child, than risk a drunk person stopping a machine that can do its job just fine on its own, thank you very much.

No no no - wait - that would be crazy talk. Of course an escalator needs an emergency stop button. Even if drunk people might press it.

However Chris Urmson of Google thinks that letting humans override machines is “crazy”:

“...[if] we put an extra steering wheel or brake pedal there for the passenger to grab ahold of anytime. It would just be crazy to think about doing that...

...I think the idea that you want the person to jump in who hasn’t been paying attention or maybe had a couple of drinks with dinner and then jump in to override is probably not the right idea.”


But here’s a worry about autonomous vehicles: There’s a distinct potential that one could be hijacked, by hackers, for say, the purpose of kidnapping. Would it not be wise to have some sort of emergency brake or cut-off installed? Or do we just expect a passenger to leap from a moving vehicle if they realize it is not going where they expected it to go?

We’ve seen numerous examples of cars being “hacked” in various ways recently, so it’s not as though the danger is implausible.


There may also be instances where another occupant is threatening or endangering other passengers - there should obviously be a way for a passenger to stop the vehicle immediately in such situations.

Or suppose a more simple problem, the primary brake system fails - the vehicle should have a back-up, which should be able to be operated by occupants. Cars have hand brakes too - and they’re not constantly being jammed on by drunk backseat occupants.


Whatever danger is posed by emergency brakes, is minimal, if not completely negligible. And even if the technology developed to the point where they were completely unnecessary, the mere existence of the control would be important to securing the confidence of users.

My problem with Melissa Walker’s article is not the reporting of things other people are saying - it’s the lack of questioning what they’re saying. Even if the questions seem dumb or basic at the time. Just taking the word of somebody who has a vested interest in a product isn’t really doing a service for readers.