Stopping distances come up in the UK driving theory test again and again, and they confuse learners more than almost any other topic. The numbers look arbitrary, the two distances get mixed up, and the wet and icy weather rules add another layer on top. This guide explains the Highway Code figures in plain language, shows you how to remember them, and covers the questions the theory test actually asks.
What is a stopping distance?
Your overall stopping distance is the distance your car travels from the moment you first notice a hazard to the moment it comes to a complete stop. It is made of two parts added together:
- Thinking distance is the distance you travel while you see the hazard,
decide what to do, and move your foot to the brake. Nothing has happened to the car yet — it is still travelling at full speed.
- Braking distance is the distance you travel from the moment the brakes
start working until the car stops.
Stopping distance = thinking distance + braking distance. Every figure in the Highway Code table follows that simple sum. If you can remember the two parts, you can work out the total, and the theory test asks about both parts separately as well as the total.
Highway Code rule 126, which covers stopping distances, says to drive at a speed that will allow you to stop well within the distance you can see to be clear, and to leave enough space between you and the vehicle in front so that you can pull up safely if it suddenly slows down or stops. The safe rule, in the Highway Code's own words, is never to get closer than the overall stopping distance.
The Highway Code table
The table below is the Highway Code's "Typical stopping distances" chart that accompanies rule 126. The figures are for a car with good brakes and tyres, on a dry road, with an alert driver. They are typical distances, not exact ones — your real stopping distance will be longer if you are tired, if the road is wet, or if your tyres or brakes are worn. Car lengths assume an average car of about 4 metres.
| Speed | Thinking distance | Braking distance | Overall stopping distance | In feet | Car lengths |
|---|---|---|---|---|---|
| 20 mph | 6 m | 6 m | 12 m | 40 ft | 3 |
| 30 mph | 9 m | 14 m | 23 m | 75 ft | 6 |
| 40 mph | 12 m | 24 m | 36 m | 118 ft | 9 |
| 50 mph | 15 m | 38 m | 53 m | 175 ft | 13 |
| 60 mph | 18 m | 55 m | 73 m | 240 ft | 18 |
| 70 mph | 21 m | 75 m | 96 m | 315 ft | 24 |
Three figures in this table do most of the work in the theory test. At 30 mph, the typical overall stopping distance is 23 metres: 9 metres of thinking distance plus 14 metres of braking distance. At 50 mph it is 53 metres. At 70 mph it is 96 metres — 21 metres thinking plus 75 metres braking, about twenty-four car lengths. If you remember 23, 53 and 96, you have the answers to the most commonly asked questions.
How to remember the numbers
The table looks like twelve unrelated numbers, but it is built from two simple patterns. Learn the patterns and you can rebuild the whole table from memory.
Thinking distance is the easy one. It rises steadily, by 3 metres for every extra 10 mph. In metres, it is just the speed multiplied by 0.3: 20 mph gives 6 metres, 30 mph gives 9, 40 gives 12, 50 gives 15, 60 gives 18, and 70 gives 21. That steady rise reflects the fact that thinking distance depends on your reaction time, which stays roughly the same whatever speed you are travelling at — the chart assumes about two-thirds of a second to react — so the distance grows in direct proportion to speed.
Braking distance is the one that catches people out, because it grows much faster than speed. Braking distance rises with the square of speed: double the speed and the braking distance roughly quadruples. From 30 mph to 60 mph the speed doubles, but the braking distance goes from 14 metres to 55 metres — almost four times as far. That is why the overall stopping distance at 70 mph (96 metres) is four times the distance at 30 mph (23 metres) even though the speed has only just over doubled. Speed is the dominant factor in stopping distance, and it punishes small increases: the difference between 60 mph and 70 mph alone adds 23 metres, nearly six car lengths, to your stopping distance.
A useful way to practise is to say the overall totals in order until the rhythm sticks: 12, 23, 36, 53, 73, 96. Then add the two parts for the speeds the test asks about most often — 30 mph (9 + 14 = 23) and 70 mph (21 + 75 = 96).
The two-second rule
The table tells you how far you need, but on the road you cannot measure metres. The Highway Code gives you a time-based method instead. Rule 126 says to allow at least a two-second gap between you and the vehicle in front on roads carrying faster-moving traffic and in tunnels where visibility is reduced. Pick a fixed point, such as a sign or a bridge, and count as the vehicle ahead passes it. If you reach the same point in less than two seconds, you are too close.
The gap should be at least doubled on wet roads — four seconds — and increased still further on icy roads. Rule 126 also says that large vehicles and motorcycles need a greater distance to stop than a car, and that if you are driving a large vehicle in a tunnel you should allow a four-second gap. If you have to stop in a tunnel, leave at least a 5-metre gap between you and the vehicle in front.
The theory test asks about the two-second rule directly, so learn the number and the conditions: two seconds in the dry, four seconds in the wet, and more still on ice. A common mistake is to answer with a distance in metres when the question asks for a time gap, or the other way round. Read the question carefully and check whether it wants seconds or metres.
Wet and icy roads
The figures in the table are for a dry road. In wet weather, stopping distances are at least double those on dry roads, so your two-second gap becomes at least four seconds. On icy roads, stopping distances can be up to ten times greater. Those multipliers come from the Highway Code: rule 126 for the doubling on wet roads, and rules 227 and 230 for wet and icy conditions.
That is worth pausing on, because it shows how quickly a safe gap becomes an unsafe one. At 30 mph your dry stopping distance is 23 metres. In the wet, expect at least 46 metres. On ice, it could be 230 metres — more than two football pitches. The theory test asks about these multipliers, and the answers are always the same: at least double in the wet, up to ten times greater on ice.
What makes stopping distances longer?
The table assumes the best case: a dry road, good tyres, working brakes, and an alert driver. Real life is usually worse, and the theory test asks what makes stopping distances longer. The factors split neatly between the two parts of the distance.
Thinking distance gets longer when anything slows your reactions. Tiredness is the biggest one. Alcohol and drugs slow reactions even in small amounts. Distraction — a phone, a conversation, looking away from the road — adds time before you even start to brake. Age and illness can slow reactions too. Anything that delays the decision to brake stretches the thinking distance, and at motorway speeds every extra fraction of a second costs several metres.
Braking distance gets longer when anything reduces grip or braking power. Worn tyres, under-inflated tyres, and worn brakes all add distance. A wet, icy or loose road surface reduces grip. A heavily loaded car takes longer to stop. And speed, as above, has the largest effect of all, because braking distance grows with the square of speed.
If a theory question asks what affects thinking distance, think about the driver. If it asks what affects braking distance, think about the car, the road and the weather. That split answers a whole family of questions.
How the theory test asks about stopping distances
Stopping distance questions in the multiple-choice section usually take one of four forms. The first asks for a figure: what is the typical stopping distance at 30 mph (23 metres), or at 70 mph (96 metres)? The second asks for one part: what is the thinking distance at 50 mph (15 metres), or the braking distance at 40 mph (24 metres)? The third asks about conditions: how do stopping distances change on a wet road (at least double), or on an icy road (up to ten times greater)? The fourth asks about the gap: how large a gap should you leave on a fast road (at least two seconds), and what should you do with it in the wet (double it)?
The most common mistakes are answering with the thinking distance when the question asked for the overall distance, mixing up feet and metres, and forgetting that the table is for a dry road in good conditions. When a question gives you a speed and asks for a distance, check which distance it wants — thinking, braking or overall — before you pick an answer.
Practise it on the road
The numbers matter most when you are actually driving. On your next lesson, try the two-second check on a faster road: pick a fixed point, count as the car ahead passes it, and see whether you reach it in less than two seconds. On a wet day, count to four instead. It is a small habit, but it turns a table you memorised for a test into a judgement you can use every time you drive — which is, after all, what the Highway Code is for.
Sources (checked 5 November 2026)
- Highway Code rule 126, "Stopping distances", and the "Typical stopping
distances" table — reproduced verbatim at https://mocktheorytest.com/resources/general-rules-techniques-and-advice-for-all-drivers-and-riders-control-of-the-vehicle/ (rule 126 text and all six rows of the table verified here)
- Highway Code rule 126 table, corroborated identically by
https://www.thelicensedesk.com/theory-test/safety-margins/ (checked against the Highway Code as amended 22 October 2025), https://liveaccidenttracker.com/stopping-distance (tables checked against the Highway Code, GOV.UK, updated 2 November 2026), https://www.drivingtheory4all.co.uk/learning-to-drive/stopping-distances and https://undergroundmathematics.org/calculus-meets-functions/keep-your-distance
- Wet roads at least double, icy roads up to ten times greater (Highway
Code rules 126, 227 and 230) — corroborated by https://www.thelicensedesk.com/theory-test/safety-margins/ and https://drivingtheorytestcoach.co.uk/highway-code-explained/stopping-distances-theory-test/
- Review of the Highway Code on motorways and high-speed roads, including
Verification notes and gaps
- The Highway Code rule 126 table in this draft was verified against six
independent sources that reproduce it identically, including one that quotes the full rule 126 text verbatim. The GOV.UK Highway Code guidance page itself did not surface in web search during this session, so the table was NOT read directly on GOV.UK. The numbers are consistent across every source checked (20 mph: 6/6/12; 30 mph: 9/14/23; 40 mph: 12/24/36; 50 mph: 15/38/53; 60 mph: 18/55/73; 70 mph: 21/75/96), and the feet and car-length figures (40/75/118/175/240/315 ft; 3/6/9/13/18/24 car lengths) match across sources. A direct GOV.UK read is recommended before publishing.
- The "about two-thirds of a second" reaction-time assumption behind the
thinking-distance figures is stated by two of the sources checked and is consistent with the table (thinking distance = speed × 0.3 in metres). It is presented as the chart's assumption, not as a Highway Code rule.
- No test-centre names, pass rates, waiting times or instructors appear in
this draft. No phone numbers appear in any of the three drafts.