What are the correct UK stopping distances?

Friday 28th June 2024

Following other cars too closely (tailgating) is one of the biggest causes of road accidents in the UK and if you tailgate during your driving test it can result in a fail. Knowing the correct thinking, braking and stopping distances are essential to keep yourself and other road users safe. Learn how to calculate stopping distances and what affects stopping distances in our article. 

What is stopping distance?

Stopping distance is the total distance it takes your vehicle to come to a complete stop when braking at various speeds. The faster your car is travelling, the longer it takes for it to come to a halt. When considering your vehicle’s stopping distance, remember this formula: 

Thinking Distance + Braking Distance = Stopping Distance

Source: The AA

Why is stopping distance important? 

Having a clear understanding of stopping distances is crucial as a driver. This empowers you to make better-informed decisions while taking necessary precautions to prevent accidents and ensure the safety of all road users. 

Maintaining the correct stopping distances ensures you: 

• React in time when other motorists need to emergency brake 

• Get a clearer view of the road ahead. 

• Manage fuel economy and avoid braking harshly. 

What is thinking distance?

Thinking distance is the time (equated by distance) it takes to press the brake pedal to react to the hazard ahead. According to the official UK Highway Code, and based on a car of around four metres in length, thinking distance can be calculated like this: 

Source: RAC

What is braking distance?

Braking distance refers to how far your vehicle continues to travel after applying the brakes. Based on an average passenger car, the braking distance can be calculated as: 

Source: RAC

How to calculate the stopping distance

Driving theory tests often include questions regarding stopping distances. Calculating stopping distances will help you pass your test and keep you safe on the roads long after passing. The stopping distance calculations below will help. However, this is based on an average-sized family car in normal weather conditions and if the driver is not distracted or impaired. When working out the stopping distance, use the following formula: 

Starting with 20mph, multiply the speed intervals by 2 to give the safe stopping distance in feet. For each additional 10mph, increase the multiplication by 0.5 to provide the appropriate stopping distance: 

• 20 mph x 2 = 40 feet (12 metres or 3 car lengths) 

• 30 mph x 2.5 = 75 feet (23 metres or 6 car lengths) 

• 40 mph x 3 = 118 feet (36 metres or 9 car lengths) 

• 50 mph x 3.5 = 175 feet (53 metres or 13 car lengths) 

• 60 mph x 4 = 240 feet (73 metres or 18 car lengths) 

• 70 mph x 4.5 = 315 feet (96 metres or 24 car lengths) 

What can affect car stopping distances?

Aside from the stopping distance formula, there are other factors which can affect your vehicle’s stopping distance: 

• The weather 

• Road conditions 

• The condition of your car 

• Driving style 

• Tyre tread 

Have you noticed a difference in your vehicle’s performance or stopping distances? Your car’s brakes or tyres may require inspecting or replacing. Buy your tyres online or book a free brake check by contacting your local Formula One Autocentres branch today.