Do you know your stopping distances?

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

Stopping distance and driving speed

The required stopping distance increases the faster that the vehicle is travelling.

For example, for a car, the stopping distance at 30mph, in normal driving conditions is 23 metres (or 75 foot). In comparison, for a car travelling at 70mph in normal conditions, the required stopping distance increases to 96 metres (315 foot)

Stopping distances for cars: What are the stopping distances?

The official stopping distances for cars, as per the Highway Code are as follows:

Weather and stopping distance

Stopping distance is affected by how fast you're driving - but also by the weather.

Stopping distances in wet or icy conditions are longer than the stopping distances when driving in dry conditions.

The Highway Code advises your total stopping distance in wet conditions will be at least double the distance it takes to stop on a dry surface, and 10 times more in snow and ice!

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)

Braking distance

The braking distance refers to how far your car travel whilst braking, in an attempt to bring your car to an emergency stop.

What are the braking distances of a car?

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

1. Locate a fixed point on the road ahead, such as a lamppost.
2. Look to see when the vehicle ahead passes that point.
3. Ensure at least 2 seconds have passed before you reach the same point.