Final answer:
The distance a vehicle travels as the driver reacts and steps on the brake is known as the reaction distance, which is part of the overall stopping distance that also includes the braking distance.
Step-by-step explanation:
The distance your vehicle travels when you move to step on the brake is called your reaction distance. This distance is part of the total stopping distance, which also includes the braking distance.
The reaction distance is the length the vehicle travels during the driver's reaction time, which averages around 0.500 seconds. The braking distance is the length the vehicle travels from the time the brakes are applied to when it comes to a complete stop, which varies with speed and road conditions.
Braking distance gets significantly longer on wet pavement compared to dry pavement. The reaction distance can be calculated simply by multiplying the speed at which the vehicle is traveling by the driver's reaction time.
To ensure safety while driving, one must be aware of the combined stopping distance which includes the distance traveled during the reaction time, as well as the braking distance.