Lesson
Safety and your vehicle
You are responsible for keeping your car roadworthy. Questions cover tyres, lights, warning lights and reducing pollution.
Key rules to know
- The legal minimum tyre tread depth for cars is 1.6mm across the central three-quarters of the tread, around the whole tyre.
- Check tyre pressures when tyres are cold, using the figures in your handbook.
- Fuel use rises at higher speeds and with heavy acceleration. Smooth driving saves fuel and reduces emissions.
- You must not use your horn or fog lights to cause unnecessary noise or dazzle.
How it applies on the road
The steering feels heavy
This may indicate a problem with the power steering or an under-inflated tyre. Get it checked.
A warning light comes on
Check your handbook. A red light usually means stop as soon as it is safe.
Common mistakes
- Checking tyre pressure straight after a long drive, when tyres are warm.
- Thinking 1.6mm is 'plenty'. It is the legal minimum, and grip in the wet drops well before that.
Official sources
Content written and reviewed by Rob Cordina. Last reviewed: October 2026. Our practice questions are original, written from the Highway Code — they are not official DVSA questions. Always check the latest Highway Code.