Stopping distance

This is the distance your vehicle travels

• from the moment you realise you must brake
• to the moment the vehicle stops.

You need to leave enough space between you and the vehicle in front so that you can pull up safely if it slows down or stops suddenly.

To do this, you must be able to judge your overall stopping distance.

Practise judging distance while you’re walking. Pick out something ahead and estimate how far away it is. Check your estimate by walking the distance and measuring it against your stride. (One good stride is roughly a metre.)

Stopping distance depends on

• how fast you’re going
• whether you’re travelling on the level, uphill or downhill
• the weather and the state of the road
• the type and age of your vehicle (normally, older vehicles need a longer stopping distance)
• the condition of your brakes and tyres
• the size and weight of your vehicle
• our ability as a driver, especially your reaction times when applying the brakes.

Stopping distance divides into

• thinking distance
• braking distance.

What are the usual stopping distances?

Thinking distance

This depends on how quickly you react. It takes well over half a second for most people to react.

If you’re tired or unwell, it may take longer.

Braking distance

This depends mainly on the speed of your vehicle, although other factors can also play a part.

Allow double the normal stopping distance on wet roads and 10 times the normal distance when the roads are icy.

Your tyres will have less grip on the road where

• the road surface is loose
• any diesel is spilt on the road.

In these conditions, you’ll need more time and room to stop the vehicle.