Braking and stopping distances

By the end of this topic you can

• You can brake progressively to stop smoothly at a chosen point.
• You can keep a safe gap using the two-second rule.
• You can explain thinking distance, braking distance and overall stopping distance.
• You can adjust your gap and speed for wet or icy roads.
• You can stop quickly and under control in an emergency.

What you need to know and understand

• Overall stopping distance is thinking distance plus braking distance.
• Typical overall stopping distances in the Highway Code are 12 metres at 20 mph, 23 metres at 30 mph, 36 metres at 40 mph, 53 metres at 50 mph, 73 metres at 60 mph and 96 metres at 70 mph.
• Leave at least a two-second gap on faster roads. Double it on wet roads.
• On icy roads, stopping distances can be up to ten times greater than on dry roads.
• The safest way to brake is early and lightly, braking more firmly as needed, then easing off just before you stop.
• Anti-lock brakes (ABS) help you steer while braking hard, but do not assume they shorten your stopping distance.
• Tiredness, alcohol, drugs and distraction increase your thinking distance.

Stopping smoothly

1. Look ahead and decide early where you need to stop.
2. Check your mirrors so you know what is behind you.
3. Take your foot off the accelerator and cover the brake.
4. Press the brake gently at first, then more firmly as needed.
5. Ease the pressure off just before the car stops, so it settles without a jolt. In a manual car, press the clutch down just before stopping.

Thinking distance and braking distance

Thinking distance is how far you travel between seeing a hazard and starting to brake. It depends on you: your alertness, health and whether you are distracted. Braking distance is how far the car travels once the brakes are on. It depends on speed, the road surface, the weather, your tyres and brakes, and the weight in the car.

Speed has a huge effect. At 30 mph the typical stopping distance is 23 metres, but at 60 mph it is 73 metres, more than three times as far. Always drive at a speed that lets you stop well within the distance you can see is clear.

The two-second gap

Pick a fixed point ahead, such as a lamp post or shadow. When the vehicle in front passes it, say 'only a fool breaks the two-second rule'. If you reach the point before you finish, you are too close. In the wet, double the gap to at least four seconds. In ice and snow, leave much more.

Emergency stops

In an emergency, brake immediately and firmly, keeping both hands on the wheel. With ABS, keep firm pressure on the pedal until you have stopped or slowed enough, and steer around a hazard if needed. Without ABS, avoid braking so hard that the wheels lock. After stopping, secure the car and check all around before moving off. Your examiner may ask you to do a controlled emergency stop on the test.

Common mistakes

• Braking late and hard. Look further ahead so you can brake early and gently.
• Following too closely. Use the two-second rule and double it in the rain.
• Releasing the brake too early at a stop and rolling on. Hold the car still, using the parking brake if needed.
• Braking hard while turning. Slow down before the bend or corner.
• Pumping the pedal in a car with ABS. Keep steady, firm pressure instead.

Test yourself: Braking and stopping distances

Answer each question, then read the explanation. Questions come in a random order each time.

Go deeper

• Stopping Distances UK