>Recommended following distances are nowhere near "instant stop of vehicle in front of you plus reaction time". But the nothing can instantly stop, it's physic

>Recommended following distances are nowhere near "instant stop of vehicle in front of you plus reaction time". But the nothing can instantly stop, it's physics. The recommendations, at least in Germany are so that you have enough time to react + brake if the car in front of you does an emergency braking manœuvre. If the car merges into your lane at too little distance, like here, you have to slow down. A lot of people don't.