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6th August 2020

Do you know the stopping distance of your car?



Knowing the stopping distance of your car can be tricky, especially with all of the factors to take into account. It’s also affected by the quality and condition of your brakes and can vary depending on environmental factors. 

So what’s the best way of working out what your car’s stopping distance is and to stop yourself from tailgating? Well we’ve put together some of our best tips and tricks to help you do just that, no matter the situation.



What is stopping distance?

Stopping distance is the time it takes to bring a moving car to a stop. It can be calculated with the following formula:

Stopping distance = thinking distance + braking distance



This consists of the physical efficiency of your brakes and the time it takes you to react.



Braking distance

So how do you work out braking distance? Generally speaking, braking distance increases as the speed of the vehicle also increases. 

The Highway Code has given guidelines for braking distance required when travelling at different speeds. Although this stands as a great guideline to maintaining a safe stopping distance, there are other factors that can affect your braking distance which should be taken into account.



Factors that affect braking distance


1. Weather Conditions

Braking distance will tend to increase if roads are wet. The general rule of thumb when roads are wet is to double the distance you would usually use.

If the roads are icy, this will significantly increase your braking distance. You’ll want to break even sooner than if the roads were wet. Some advice even states that your braking distance should be 10 times longer.


2. Car Condition

The condition of your car’s brakes are a big factor in the efficiency of your braking and will significantly affect your braking distance. So make sure to keep your brakes in good working order.

Tyres also have a large part to play in your braking distance. Different tyres are given a different wet & dry grip rating, starting at A (best) to G (worst). Tyres with better grip will be more effective when braking, whereas lower grip will increase your braking distance. Both tyre pressure and tread will also impact your braking distance, so keep on top of them!



Thinking distance

Now we’ve covered braking distance, this just leaves thinking distance in order to work out what our stopping distance should be.

So what is thinking distance? Thinking distance is simply the time it takes for you to spot a hazard and then react to it. 

The Highway Code has also given guidelines for thinking distance when travelling at different speeds. These guidelines are based on a thinking (reaction) time of 0.7 seconds and this will vary from person to person.



Factors that affect thinking distance


1. Tiredness

The more tired you are, the slower your reaction time is going to be. Research shows that after driving for 2 hours, you’ll have delayed reaction times and be less able to concentrate. It’s recommended to take a break every couple of hours on longer journeys.


2. Distractions

Distractions will affect your attention to the road and can therefore increase the time it takes for you to react to a hazard. Using your mobile phone, satnav or any other in-car technology can draw your attention away from the road and increase your reaction time. Even holding conversations with passengers or via a handsfree call can avert your attention. These are all factors that you should take into account when determining your thinking distance.

It’s vital that you’re aware of your stopping distance and place enough space between yourself and the vehicle in front of you. These tips and tricks will help you work out your stopping distance and ensure you have a safe drive.