“I would like to know what the law is regarding a safe stopping distance at a stop sign if I stop behind another car at a stop sign or robot.”
There is no law or rule in regard to actual measurable distance. The K53 defensive driving standard requires that you maintain a clear space around your vehicle at all times. So one would leave enough space behind the other vehicle so that if that driver were to allow the vehicle to roll back due to lack of attention or driving skill, it would not bump into your own vehicle. Also, if he were to move off and you moved forward, and he then suddenly stops again because the road is not clear to move into the intersection, you should be able to stop safely behind him without bumping into that vehicle.
It basically boils down to judgement in order to maintain a safe and clear space between vehicles at all time.
Learner’s Licence & K53
Driving Licence Test Info