Think of reaction distance as the distance your vehicle has travelled while you react. At 100 km/h, you travel roughly 40m during the 1.5 seconds that it takes you to react.
Braking distance is the distance that it takes your vehicle to come to a full stop starting from when you start applying the brake. At 100 km/h, you need roughly 50m to stop in good conditions.Keep a speed that enables you to stop in time for a hazard on the road ahead, e.g. wildlife
Doubling the speed will increase reaction distance by 2 and braking distance by 4. Speed makes a huge difference in your ability to stop in time and a significant difference to your chance of being involved in a crash.
Wet and slippery conditions also add a significant stop
Stopping distance is affected by:
Two-stage braking will improve effectiveness, reduce the chance of skidding and provide far better control to the driver than hard braking. Hard braking can lead to a loss of control and cause skidding (particularly in poor conditions).