Topic
Safety margins
Last reviewed against gov.uk on
Safety margins covers stopping distances at each speed, how weather and the road surface change them, and the gap you need to leave around your vehicle to react safely if something goes wrong.
What’s tested
- Stopping distances from 20 to 70 mph — thinking, braking and total
- Weather multipliers: wet roads (×2), icy or snowy conditions (up to ×10)
- Aquaplaning — what it feels like and how to recover
- Driving in strong wind, especially overtaking high-sided vehicles
- Fog, mist and the use of fog lights
Key Highway Code rules
Practise real DVSA revision questions
Work through 20 real DVSA car revision questions, each with the correct answer and a full explanation — then get the full bank for every topic in the app, free to get started.
Common mistakes
- Forgetting the ×10 stopping distance multiplier on ice
- Using cruise control on a wet motorway (loss of control if aquaplaning)
- Leaving rear fog lights on after visibility improves
- Following too closely in spray from the vehicle ahead
Keep going
All 14 topics
- Alertness Staying focused: mirrors, observation, scanning the road, avoiding fatigue and distraction.
- Attitude Considerate driving: patience, following distance, behaviour at crossings and roundabouts.
- Safety and your vehicle Roadworthiness: brakes, tyres, lights, fluids, warning lights and securing the car.
- Hazard awareness Anticipating risk: spotting clues, planning ahead, reading other road users’ behaviour.
- Vulnerable road users Pedestrians, cyclists, motorcyclists, horse riders, children, older and disabled people.
- Other types of vehicle Sharing the road with lorries, buses, motorcycles, trams and emergency vehicles.
- Vehicle handling Driving in rain, fog, snow, dark and strong wind — how conditions change the car.
- Motorway rules Joining, lane discipline, speed, breakdowns and smart-motorway running lanes.
- Rules of the road Speed limits, junctions, roundabouts, parking, level crossings and one-way streets.
- Road and traffic signs The visual language of UK roads — shape, colour and meaning of every sign and signal.
- Documents Licence, insurance, MOT, V5C log book and SORN — the paperwork to be legally on the road.
- Incidents, accidents and emergencies First aid, CPR, AED, RTC procedure, breakdowns and tunnel safety.
- Vehicle loading Carrying passengers, luggage, roof loads and towing — and how each changes the car.