While being tailgated is an unpleasant experience, the truth is that many of us don't leave enough distance between ourselves and the vehicle ahead.
As such, it's a good idea to brush up on your stopping distances.
The key benefits of leaving enough distance between you and the vehicle ahead are:
- A better view of the road ahead
- More distance (time) to think and brake if you need to
- Reduced fuel consumption thanks to gentler braking and smoother driving
Stopping distance explained
Your stopping distance is the time it takes to react to a hazard (thinking distance) plus the time it takes to stop your vehicle (braking distance).
- Stopping distance = thinking distance + braking distance
Weather and driving speed
Stopping distance is affected by how fast you're driving - but also by the weather - it takes longer to stop on a wet or icy road.
Thinking distance explained
This is how long it takes to spot a hazard before applying the brakes. If there are only a few metres between you and the vehicle ahead, you will probably struggle to stop in time - particularly if the vehicle ahead brakes suddenly.
The Highway Code states that drivers have a thinking time of 0.7 seconds. The higher your speed, the further you'll go in that time.
The thinking distance can be affected (increased) by:
- Drinking alcohol and drug use (slows your reaction times)
- Distractions such as mobile phones (it is illegal to use a mobile while driving)
- Fatigue (concentration levels decrease after 2 hours of driving; take regular breaks on long-distance journeys)
The braking distance can be affected (increased) by:
Brake condition: ensure brakes are in good working order.
Suspension: Worn suspension can increase braking distance since weight transfer impacts braking effectiveness.
Weight: heavier cars will take longer to stop.
Tyres: Those with a high wet grip rating will perform better in the wet (they are rated from A - best to G - worst). Tyres with worn treads will result in an increased braking distance. Tyres should be inflated according to the manufacturer's guidelines (not under- or over-inflated, since this will increase stopping distances).
Weather: It takes longer to stop on wet or icy roads. Double the gap if it's wet and increase the gap by up to 10 times if it is icy.
Condition of the road: muddy or damaged roads may increase braking distances, so leave extra space between your vehicle and the one ahead.
The 2-second rule
As a rule of thumb, there should be 2 seconds between you and the vehicle ahead to keep at a safe distance.
How to implement the 2-second rule
- Locate a fixed point on the road ahead, such as a lamppost.
- Look to see when the vehicle ahead passes that point.
- Ensure at least 2 seconds have passed before you reach the same point.