Photo: Dominik Gryzbon / Pexels. Illustrative photograph.
In Great Britain, the Highway Code gives a typical stopping distance for a car of 12 metres at 20 mph, rising to 96 metres at 70 mph on a dry road. Rule 126 says to leave at least a two-second gap on high-speed roads, at least double that in the wet, and up to ten times more on ice. This explainer is for learner drivers in England, Scotland and Wales, and for the parents helping them practise. It breaks down the official figures, shows how to measure a two-second gap, and covers the braking rules (117 to 122) that sit alongside it.
Key facts
- Stopping distance = thinking distance + braking distance. The Highway Code diagram shows both parts for each speed.
- At 30 mph: 23 metres in total, which the Highway Code says is about six car lengths.
- At 70 mph: 96 metres in total, or about twenty-four car lengths.
- Two-second gap: the minimum on high-speed roads and in tunnels (Rule 126).
- Wet roads: stopping distances are at least double (Rules 126 and 227).
- Icy roads: the gap may need to be up to ten times greater (Rules 126 and 230).
The Highway Code stopping distances table
These are the figures from the “Typical stopping distances” diagram published with Rule 126. The Highway Code uses an average car length of 4 metres (13 feet) for the car-length comparison.
| Speed | Thinking distance | Braking distance | Overall stopping distance | Roughly |
|---|---|---|---|---|
| 20 mph (32 km/h) | 6 m | 6 m | 12 m (40 feet) | 3 car lengths |
| 30 mph (48 km/h) | 9 m | 14 m | 23 m (75 feet) | 6 car lengths |
| 40 mph (64 km/h) | 12 m | 24 m | 36 m (118 feet) | 9 car lengths |
| 50 mph (80 km/h) | 15 m | 38 m | 53 m (175 feet) | 13 car lengths |
| 60 mph (96 km/h) | 18 m | 55 m | 73 m (240 feet) | 18 car lengths |
| 70 mph (112 km/h) | 21 m | 75 m | 96 m (315 feet) | 24 car lengths |
The Highway Code describes these as a general guide. The real distance depends on your attention (which affects thinking distance), the road surface, the weather and the condition of your vehicle at the time.
Spot the pattern
Look down the thinking distance column: it goes up by 3 metres for every extra 10 mph. Thinking distance grows in step with speed because you cover more ground in the same reaction time.
Braking distance behaves differently. Going from 30 mph to 60 mph doubles your speed, but braking distance goes from 14 metres to 55 metres, nearly four times as far. That is why a small increase in speed makes a big difference to whether you can stop in time.
How to remember the figures for the theory test
Stopping distances come up in the safety margins topic of the theory test. One way to learn them without memorising six random numbers:
- Learn the thinking distances first: 6, 9, 12, 15, 18, 21 metres. Each one is the speed’s first digit multiplied by 3.
- Learn the totals: 12, 23, 36, 53, 73, 96 metres.
- If you need a braking distance, subtract the thinking distance from the total. At 50 mph, 53 minus 15 gives 38 metres.
What is the two second rule?
Rule 126 tells you to drive at a speed that lets you stop well within the distance you can see to be clear. It says the safe rule is never to get closer than the overall stopping distance, and to allow at least a two-second gap between you and the vehicle in front on high-speed roads and in tunnels where visibility is reduced.
How to measure a two-second gap
- Pick a fixed point ahead, such as a road sign, bridge or lamp post. The Highway Code illustration uses a sign.
- When the rear of the vehicle in front passes that point, start counting two seconds at a steady pace.
- If you reach the point before you finish counting, you are too close. Ease off and count again.
A time gap works at any speed, which is why it is easier to use than trying to judge metres. The faster you go, the more ground two seconds covers.
When to leave more than two seconds
| Condition | What the Highway Code says |
|---|---|
| Dry, high-speed road | At least a two-second gap (Rule 126) |
| Wet road | The gap should be at least doubled; stopping distances will be at least double (Rules 126 and 227) |
| Icy or snowy road | Up to ten times greater; stopping distances can be ten times greater than on dry roads (Rules 126 and 230) |
| Following a large vehicle or motorcycle | Remember they need a greater distance to stop (Rule 126) |
| Stopped in a tunnel | Leave at least a 5-metre gap to the vehicle in front (Rule 126) |
Rule 227 explains why the wet makes such a difference: your tyres have less grip on the road. If the steering suddenly feels unresponsive, water is probably stopping the tyres gripping. Ease off the accelerator and slow down gradually. For more on bad weather, see driving in rain, ice, fog, wind and heat.
Tailgating
The Highway Code defines tailgating as leaving a gap so small that you could not stop safely if the vehicle in front braked suddenly. It calls tailgating dangerous and intimidating, and says the police enforce dangerous and careless driving offences such as tailgating. If someone overtakes and pulls into your gap, Rule 168 says drop back to restore a two-second gap. Read more in tailgating and road rage.
If someone is following you too closely, don’t brake to make a point or speed up to get away. Leave a bigger gap in front, so that if you need to slow down you can do it gently, and let them pass when it is safe. Two seconds is a minimum check in good conditions, not a target: grow the gap whenever grip, visibility or your own concentration is worse than usual.
In slow-moving traffic, Rule 151 lets you close up to keep traffic flowing, but you should never get so close that you cannot stop safely, and you should leave room to steer round a vehicle that breaks down.
Braking and control: Rules 117 to 122
Stopping distances assume you brake well. The control rules set out how.
- Normal braking (Rule 117): brake early and lightly, more firmly as you begin to stop, then ease off just before the car stops to avoid a jerk.
- Emergency braking (Rule 118): brake immediately, but try not to brake so harshly that the wheels lock, because locked wheels can lead to loss of control.
- Skids (Rule 119): skids are usually caused by harsh braking, accelerating or steering, or by going too fast for the conditions. Remove the cause by releasing the brake fully or easing off the accelerator, then steer in the direction of the skid. If the rear skids to the right, steer right.
- ABS (Rule 120): follow the vehicle handbook. In an emergency, press the footbrake firmly and keep the pressure on until you have slowed enough. ABS should help you keep steering control, but do not assume it will stop you in a shorter distance.
- Brakes after deep water (Rule 121): test them gently at the first safe opportunity. If they are not fully effective, apply light pressure while driving slowly to dry them out.
- Coasting (Rule 122): travelling in neutral or with the clutch down removes engine braking, lets speed build quickly downhill, makes the footbrake work harder and affects steering on bends.
Your examiner may ask you to do an emergency stop on the practical test. See driving test manoeuvres for how the test works.
Scenario: a wet dual carriageway at 60 mph
You are driving at 60 mph on a dual carriageway in steady rain. The dry overall stopping distance at 60 mph is 73 metres. Rule 227 says wet stopping distances will be at least double, so you should allow for well over 140 metres. In practice, that means counting at least four seconds behind the car ahead rather than two, and easing your speed if spray is cutting your view.
Common questions
What is the stopping distance at 30 mph in the UK?
The Highway Code gives 23 metres (75 feet): 9 metres thinking distance and 14 metres braking distance. That is about six car lengths.
What is the stopping distance at 70 mph?
96 metres (315 feet): 21 metres thinking and 75 metres braking, or about twenty-four car lengths.
Is the two second rule a legal requirement?
Rule 126 uses advisory wording (“should”), so not following it is not an offence in itself. But the Highway Code can be used as evidence in court, and driving too close can amount to careless or dangerous driving, which are offences.
How much space should I leave on ice?
Rule 126 says the gap may need to be up to ten times greater than on a dry road, and Rule 230 says icy or snowy stopping distances can be ten times greater.
Do the stopping distances apply to all cars?
They are a general guide for a typical car. The Highway Code says your attention, the road surface, the weather and the condition of your vehicle all change the real figure.
Does ABS mean I stop sooner?
Not necessarily. Rule 120 says ABS should let you keep steering control, but you should not assume it stops the car in a shorter distance.
Back to the main guide: Learning to Drive in Great Britain.
Sources
- Department for Transport, “The Highway Code: General rules, techniques and advice for all drivers and riders (103 to 158)” (gov.uk)
- Department for Transport, “The Highway Code: Typical stopping distances” diagram (assets.publishing.service.gov.uk)
- Department for Transport, “The Highway Code: Driving in adverse weather conditions (226 to 237)” (gov.uk)
- Department for Transport, “The Highway Code: Using the road (159 to 203)” (gov.uk)
- Department for Transport, “The Highway Code: Introduction” (gov.uk)