Se denomina tiempo de reacción...

Reaction time is the time from when the driver sees an obstacle until they react. It varies with the driver's physical and mental state, never with the speed or the condition of the road. Although it may seem that reacting to an obstacle or an unexpected situation should be instant, a driver's average reaction time is about 0.75 seconds. Reaction distance is the number of metres the vehicle travels during the reaction time. It depends on the reaction time and on the speed (the higher the speed, the more metres travelled in the same time). Braking distance is the distance the vehicle travels from when the driver brakes until the vehicle stops. Stopping distance is reaction distance plus braking distance. So stopping distance is the distance the vehicle travels from when the driver notices a hazard until the vehicle comes to a complete stop.