Driving lesson. Clearance

Leaving the correct distance between you and the vehicle in front will greatly reduce the chances of you hitting the back of it in the event of an emergency.

The most commonly used guide to keep your distance from the car in front is "The 2 second rule" This is a useful guide to help you keep a safe distance from the vehicle in front on a dry road. The " second rule" should be doubled to 4 seconds in wet conditions and to approximately 10 seconds in frost and icy conditions.
It works by counting to 2 when driving behind the car in front and making sure you dont pass a fixed point on the road within the 2 seconds. Give it a try.

Another guide you could follow is to leave 1 metre of space between you and the car in front for every kilometre per hour speed you travel..

When overtaking a parked vehicle, pedestrian or cyclist allow enough space for the vehicle door to open unexpectedly, enough space for the pedestrian to trip and fall and enough space in case the cyclist wobbles and falls off their bike.