As humans we know our reaction times - you naturally slow down as you get to a junction or navigate crowded or tricky traffic conditions to give yourself as much of a chance as possible to react.
This is the thinking behind many types of speed control street layouts. You should also know where to look to anticipate where danger is most likely to come from, and be ready with some kind of action. This is why we do
hazard identification tests as part of the driving test - looking in the right directions at the right times is crucial for operating a vehicle safely.
250ms is a fairly average reaction time for something visual that you are ready for - but you should really be giving yourself as much time as possible - if somebody bombs past a traffic light at 70mph, even if it is green, most people would agree that it was an unsafe move. This goes doubly for an autonomous car, that is unable to play the positioning negotiation game that humans are masters of as a result of being social creatures.
It's very easy to configure a program to slow down before intersections. Also if we want to be realistic here, you're going to be able to see that the other car isn't slowing properly for much longer than 200ms. You'd either already be braking when you hit that pause, or you'd be so early on that the delay doesn't make a real difference.
And if you're not hovering your foot over the brake pedal, you're not getting 250ms.
This is the thinking behind many types of speed control street layouts. You should also know where to look to anticipate where danger is most likely to come from, and be ready with some kind of action. This is why we do hazard identification tests as part of the driving test - looking in the right directions at the right times is crucial for operating a vehicle safely.
250ms is a fairly average reaction time for something visual that you are ready for - but you should really be giving yourself as much time as possible - if somebody bombs past a traffic light at 70mph, even if it is green, most people would agree that it was an unsafe move. This goes doubly for an autonomous car, that is unable to play the positioning negotiation game that humans are masters of as a result of being social creatures.