Typical Stopping Distances Depending on Speed & Vehicle

We all know that we need to leave a gap between the car in front of us as that space could be vital if we need to get stopped quickly – But how many of us actually do this in every day life?

A simple rule of thumb that driver’s should remember is: Only a fool breaks the two second rule and if you’re driving in the wet then you need to at least double the gap to 4 seconds between you and the car in front. The easiest way of keeping this gap is have a fixed point to measure the gap between you and the car that is ahead of you on the road. Lamp posts are a good fixed example to use.

If conditions are icy then this gap should be further increased, as there is a larger risk of going into a slide when braking on ice. It is always a good idea to come off and on the brake pedal when trying to get stopped in a hurry as this means you are minimizing the chances of the car locking up and losing control of the vehicle under braking.

If you are driving a vehicle larger than a passenger car or a motorcycle, then you will need more than a two second gap in the dry and more than four seconds in the wet as these vehicles are much more difficult to get stopped quickly.

Tunnels are few and far between in the UK compared to mainland Europe but remember that you’ll need at least four seconds of a gap as visibility is reduced. If you need to stop in a tunnel for any reason try to leave at least 5 metres between you and the car in front.

When driving at speed, like on a dual carriageway or a motorway you should always obey the rule of thumb (above) and if a car pulls into the space you have left for your own safety then ease off and create a new safety gap.

Typical stopping distances when in dry conditions (Source: DSA)

• 20mph= 6m of thinking distance and 6m of braking distance – This is equal to 12m or (40 feet) or three car lengths.
• 30mph= 9m of thinking distance and 14m of braking distance – This is equal to 23m or (75 feet) or six car lengths.
• 40mph= 12m of thinking distance and 24m of braking distance – This is equal to 36m or (118 feet) or nine car lengths.
• 50mph= 15m of thinking distance and 38m of braking distance – This is equal to 53m or (175 feet) or thirteen car lengths.
• 60mph= 18m of thinking distance and 55m of braking distance – This is equal to 73m or (240 feet) or eighteen car lengths.
• 70mph= 21m of thinking distance and 75m of braking distance – This is equal to 96m or (315 feet) or twenty-four car lengths.

These stopping distances are not exact as these are pre-determined as if the road is dry, that you are completely concentrating on the road ahead and the motorists around you and that you car is well maintained and the road surface is in good condition.

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