Braking distance

Once the brakes are applied, a braking force acts to slow the vehicle down. It still travels some distance before coming to rest. This second part of the journey is its braking distance.

Higher speed increases braking distance. At the same mass, a faster vehicle has more kinetic energy to transfer before stopping. If the braking force stays constant, braking distance is proportional to speed squared: doubling the speed makes braking distance four times as large.