---
title: "Stopping Distances & Safety Margins | The License Desk"
url: https://www.thelicensedesk.com/theory-test/safety-margins/
updated: 2026-09-26
---

> Source: https://www.thelicensedesk.com/theory-test/safety-margins/ — last reviewed 2026-09-26. Markdown version generated at build time from the same content the page serves.

DVSA theory test topic guide

# Stopping Distances & Safety Margins

Stopping distances, weather conditions, skids and keeping space around your car.

[Practise 45 Safety Margins questions](/theory-test/safety-margins/practice-test/)

Quick answer

Learn the Highway Code stopping distances from 20 to 70 mph, the two-second rule, and how rain, ice, fog and road works change the gap you need.

## What are the typical stopping distances in the Highway Code?

The Highway Code’s typical stopping distances run from 12 metres at 20 mph to 96 metres at 70 mph. Each figure is thinking distance plus braking distance. They are a general guide only: your attention, the road surface, the weather and the condition of your vehicle all change the real distance.

| Speed | Thinking distance | Braking distance | Overall stopping distance | 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 |

The chart uses an average car length of 4 metres (13 feet).

## What is the stopping distance at 70mph?

At 70 mph the typical overall stopping distance is 96 metres, about twenty-four car lengths. That is 21 metres of thinking distance plus 75 metres of braking distance. Compare 30 mph, where it is 23 metres: a speed just over twice as high needs more than four times the distance to stop.

The pattern is worth understanding rather than memorising blind. Thinking distance rises steadily, by 3 metres for every extra 10 mph, so you can work it out as the speed multiplied by 0.3 (50 mph gives 15 metres). Braking distance grows much faster: doubling from 30 mph to 60 mph takes it from 14 metres to 55 metres, nearly four times as far.

## How do you use the two-second rule?

Rule 126 says to leave at least a two-second gap to the vehicle in front on high-speed roads and in tunnels where visibility is reduced. Pick a fixed point, such as a sign, and note when the vehicle ahead passes it. If you reach the same point before two seconds have passed, you are too close.

The safe rule is never to get closer than the overall stopping distance. Rule 126 also says:

-   large vehicles and motorcycles need a greater distance to stop, and a large vehicle in a tunnel should allow a four-second gap
-   if you have to stop in a tunnel, leave at least a 5-metre gap to the vehicle in front
-   tailgating is dangerous and intimidating, and police enforce it as a driving offence.

If someone overtakes and pulls into the gap in front of you, drop back to restore two seconds (rule 168). In slow-moving traffic you can close up to keep traffic flowing, but never so close that you cannot stop safely (rule 151).

## How much longer does it take to stop on wet or icy roads?

In wet weather stopping distances will be at least double those on dry roads, so at least double your two-second gap (rules 126 and 227). On icy roads stopping distances can be ten times greater, and rule 126 says your gap should be up to ten times greater too. Slow down well before bends.

| Road surface | Stopping distance compared with dry | Following gap |
| --- | --- | --- |
| Dry | Typical chart figures | At least two seconds |
| Wet | At least double | At least double: four seconds or more |
| Icy | Can be ten times greater | Up to ten times greater |

If your steering becomes unresponsive in the wet, water is probably preventing the tyres from gripping the road. Ease off the accelerator and slow down gradually (rule 227). On ice, tyres make virtually no noise, and unresponsive steering may mean you are losing grip (rule 231).

## How should you keep a safe distance in fog?

Check your mirrors and slow down before entering fog (rule 234). You should be able to pull up well within the distance you can see clearly, and keep a safe distance behind the vehicle in front, because following its rear lights can give a false sense of security (rule 235). Use headlights when visibility is seriously reduced.

Rule 226 says you must use headlights then, which generally means when you cannot see for more than 100 metres. Do not speed up to get away from a vehicle that is too close behind you, and check your mirrors before slowing so your brake lights warn following drivers.

## How do road works and contraflows affect your safety margin?

Road works squeeze your margins with narrow lanes, temporary limits and queues. You must not exceed any temporary maximum speed limit, and you should keep a safe distance from the vehicle ahead (rule 288). In a contraflow there may be no permanent barrier between you and oncoming traffic, so extra care is essential.

Rule 290 says to slow down and increase your distance at the start and finish of a contraflow, because changes in the camber of the road may affect your vehicle’s stability. In narrow lanes marked by studs or temporary markings, make sure you can clearly see the lane edges ahead. Get into the correct lane in good time and do not switch lanes to overtake queuing traffic.

## Why is coasting dangerous?

Coasting means travelling in neutral or with the clutch pressed down. Rule 122 says it reduces your control because engine braking is eliminated, speed builds quickly downhill, heavier use of the footbrake can make it less effective, steering response suffers on bends, and it can be harder to select the right gear when you need it.

## What mistakes do learners make on safety margins questions?

Most mistakes come from mixing up the three columns of the stopping distance chart, or from applying dry-road rules to wet and icy conditions. Check which distance the question asks for, and what the conditions are, before you choose. These are the traps that appear most often.

-   **Thinking versus overall distance.** At 50 mph, 15 metres is thinking distance; the overall distance is 53 metres.
-   **Answering 73 metres for 70 mph.** 73 metres is the 60 mph figure; 70 mph is 96 metres.
-   **A two-second gap on a wet road.** Double it to at least four seconds.
-   **Braking hard when the steering goes light.** Ease off the accelerator instead.
-   **Assuming ABS shortens stopping distances.** Rule 120 says not to assume it does.
-   **Following tail lights in fog.** Rule 235 warns they give a false sense of security.

## Where should you go next?

Stopping distances are among the most reliable marks in the test once the chart is memorised, so drill them until they are automatic. Use the links below to practise this topic, then move on to handling in bad weather and motorway driving, where safety margins matter most.

-   [Practise safety margins questions](/theory-test/safety-margins/practice-test/)
-   [Vehicle handling topic guide](/theory-test/vehicle-handling/)
-   [Motorway rules topic guide](/theory-test/motorway-rules/)
-   [Hazard awareness topic guide](/theory-test/hazard-awareness/)
-   [Take a full mock theory test](/mock-theory-test/)
-   [Practise hazard perception](/hazard-perception/)

## Ready to test yourself on Safety Margins?

45 free Safety Margins questions in the official four-option format, each with an explained answer and the Highway Code rule it tests — with a timed test mode.

[Start the Safety Margins practice test](/theory-test/safety-margins/practice-test/)

## Frequently asked questions

**### What is the stopping distance at 30 mph?**

The Highway Code gives a typical stopping distance of 23 metres at 30 mph, or about six car lengths. That is 9 metres of thinking distance plus 14 metres of braking distance, in good conditions. Wet roads, worn tyres or a tired driver make it longer.

**### What is the two-second rule?**

Rule 126 of The Highway Code says to leave at least a two-second gap between you and the vehicle in front on high-speed roads and in tunnels where visibility is reduced. Measure it by watching the vehicle ahead pass a fixed point, such as a sign.

**### How much do stopping distances increase in the rain?**

In wet weather, stopping distances will be at least double those on dry roads, because your tyres have less grip (rule 227). Rule 126 says your gap to the vehicle in front should be at least doubled too, so leave at least four seconds instead of two.

**### What gap should you leave on icy roads?**

Rule 126 says the gap should be up to ten times greater on icy roads, and rule 230 warns that stopping distances can be ten times greater than on dry roads. Drive slowly in as high a gear as possible, and brake and accelerate very gently.

**### What is the difference between thinking distance and braking distance?**

Thinking distance is how far you travel between seeing a hazard and starting to brake. Braking distance is how far you travel once the brakes are on. Added together they make the overall stopping distance shown in The Highway Code's typical stopping distances chart.

Sources

-   [The Highway Code — General rules, techniques and advice for all drivers and riders (103 to 158)](https://www.gov.uk/guidance/the-highway-code/general-rules-techniques-and-advice-for-all-drivers-and-riders-103-to-158)
-   [The Highway Code — Typical stopping distances (PDF)](https://assets.publishing.service.gov.uk/media/65f97642aa9b760011fbda4e/the-highway-code-stopping-distances.pdf)
-   [The Highway Code — Driving in adverse weather conditions (226 to 237)](https://www.gov.uk/guidance/the-highway-code/driving-in-adverse-weather-conditions-226-to-237)
-   [The Highway Code — Road works, level crossings and tramways (288 to 307)](https://www.gov.uk/guidance/the-highway-code/road-works-level-crossings-and-tramways-288-to-307)
-   [The Highway Code — Using the road (159 to 203)](https://www.gov.uk/guidance/the-highway-code/using-the-road-159-to-203)

Sources last checked on 26 September 2026. Found an error? Email us — fixes are logged on our [corrections page](/corrections/).

## Which other theory test topics should you revise?

All 14 topics feed the same 50-question test, so revise every one. Then sit the [full free mock theory test](/mock-theory-test/) under the real time limit.

-   [Alertness](/theory-test/alertness/)
-   [Attitude](/theory-test/attitude/)
-   [Essential Documents](/theory-test/essential-documents/)
-   [Hazard Awareness](/theory-test/hazard-awareness/)
-   [Incidents, Accidents & Emergencies](/theory-test/incidents-accidents-emergencies/)
-   [Motorway Rules](/theory-test/motorway-rules/)
-   [Other Types of Vehicle](/theory-test/other-types-of-vehicle/)
-   [Road & Traffic Signs](/theory-test/road-and-traffic-signs/)
-   [Rules of the Road](/theory-test/rules-of-the-road/)
-   [Safety & Your Vehicle](/theory-test/safety-and-your-vehicle/)
-   [Vehicle Handling](/theory-test/vehicle-handling/)
-   [Vehicle Loading](/theory-test/vehicle-loading/)
-   [Vulnerable Road Users](/theory-test/vulnerable-road-users/)