Topic
Safety margins
Last updated
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 (×2), icy (×10), snow (significantly more)
- 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
Try a real DVSA question
Practice question
From the DVSA question bank
How much can stopping distances increase in icy conditions?
Show explanation
The correct answer is D.
Tyre grip is greatly reduced in icy conditions. For this reason, you need to allow up to ten times the stopping distance you would allow on dry roads.
Want more practice? Get 750+ free DVSA questions, hazard perception clips and the latest Highway Code in our app.
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.