Safety margins practice questions

1. On a high-speed road in good, dry conditions, what is the minimum time gap you should leave behind the vehicle in front?

Answer: At least two seconds

Leave at least a two-second gap on high-speed roads. This gives you time to react and stop if the car in front brakes.

2. It is raining heavily. How should you change your following gap compared with dry roads?

Answer: Make it at least double

In wet weather stopping distances are at least double those on dry roads, so your gap should be at least doubled.

3. On icy roads, how much longer can stopping distances be than on dry roads?

Answer: Up to ten times longer

On icy or snowy roads, stopping distances can be ten times greater than on dry roads.

4. According to the typical stopping distances in the Highway Code, what is the overall stopping distance for a car at 30 mph on a dry road?

Answer: 23 metres

The Highway Code shows a typical overall stopping distance of 23 metres at 30 mph. That is thinking distance plus braking distance.

5. According to the typical stopping distances in the Highway Code, what is the overall stopping distance for a car at 70 mph on a dry road?

Answer: 96 metres

At 70 mph the typical overall stopping distance is 96 metres. That is about the length of a football pitch.

6. When MUST you use headlights because of poor visibility?

Answer: When you generally can't see for more than 100 metres

You must use headlights when visibility is seriously reduced, generally when you cannot see for more than 100 metres.

7. Fog comes down on your drive back from a festival. The car in front is easy to follow because you can see its red lights. Why is sticking close to it a bad idea?

Answer: It can feel safe, but you may be too close to stop

In fog, rear lights can give a false sense of security. Keep a safe gap and drive so you can stop within the distance you can see.

8. How should you drive on an icy road?

Answer: Slowly, in a high gear, braking gently and early

On ice, drive slowly in as high a gear as possible. Accelerate and brake very gently, and brake progressively before bends.

9. Traffic stops in a road tunnel. What is the minimum gap you should leave to the vehicle in front?

Answer: At least 5 metres

If you have to stop in a tunnel, leave at least a 5-metre gap to the vehicle in front.

10. Using the Highway Code's typical stopping distances, what happens to the overall stopping distance if you double your speed from 30 mph to 60 mph?

Answer: It more than triples, from about 23 m to 73 m

Braking distance grows much faster than speed. The typical figures go from 23 metres at 30 mph to 73 metres at 60 mph.

11. Your car has ABS (anti-lock brakes). What does the Highway Code say about it?

Answer: It helps you steer, but may not stop you any shorter

ABS can help you steer while braking hard, but it does not guarantee a shorter stop. You still need safe gaps.

12. Using the Highway Code's typical figures, what is the overall stopping distance for a car at 20 mph?

Answer: 12 metres

Rule 126's typical stopping distances show 12 metres at 20 mph: 6 m thinking plus 6 m braking.

13. Using the Highway Code's typical figures, what is the overall stopping distance for a car at 40 mph?

Answer: 36 metres

Rule 126's typical stopping distances show 36 metres at 40 mph: 12 m thinking plus 24 m braking.

14. Using the Highway Code's typical figures, what is the overall stopping distance for a car at 50 mph?

Answer: 53 metres

Rule 126's typical stopping distances show 53 metres at 50 mph: 15 m thinking plus 38 m braking.

15. Using the Highway Code's typical figures, what is the thinking distance at 30 mph?

Answer: 9 metres

At 30 mph the typical thinking distance is 9 metres. Braking adds 14 metres, giving 23 metres overall.

16. Using the Highway Code's typical figures, what is the braking distance alone at 70 mph?

Answer: 75 metres

At 70 mph the typical braking distance is 75 metres. Add the 21 metre thinking distance for 96 metres overall.

17. You've been up most of the night revising. Which part of your stopping distance is most likely to get longer?

Answer: Your thinking distance

Overall stopping distance is thinking plus braking distance. Your physical and emotional state, such as tiredness, affects thinking distance.

18. It's raining hard on your way to work. Which part of your stopping distance does the wet road make longer?

Answer: Your braking distance

Road and weather conditions affect braking distance. Your own condition affects thinking distance.

19. Overall stopping distance is made up of which two parts?

Answer: Thinking distance and braking distance

Stopping distance is split into thinking distance (before you brake) and braking distance (while braking).

20. Your cousin drives a lorry. In a tunnel, what gap does the Highway Code say a large vehicle should keep to the vehicle in front?

Answer: A four-second gap

Rule 126 says large vehicles need more distance to stop, and a large vehicle should keep a four-second gap in a tunnel.

21. In thick fog you need to slow for a junction. Why does the Highway Code say to use your brakes, not just lift off?

Answer: So your brake lights warn drivers behind

Rule 235 says in fog, use your brakes so that your brake lights warn drivers behind you that you are slowing down.

22. You can see a bank of fog across the road ahead. What should you do before you drive into it?

Answer: Check your mirrors and slow down

Rule 234 says before entering fog, check your mirrors then slow down.

23. You switched on your rear fog light in thick fog. Now the fog has lifted and you can see a long way. What should you do?

Answer: Switch it off now that you can see

Rule 236 says you MUST switch fog lights off when visibility improves. Left on, they can dazzle drivers behind and hide your brake lights.

24. In thick fog, what danger does the Highway Code tell you to look out for?

Answer: Vehicles that don't have their lights on

Rule 235 says in fog, be aware of others not using headlights, as well as using your own lights as required.

25. On a snowy road you come up behind a snowplough. When may you overtake it?

Answer: Only if the lane you'll use has been cleared

Rule 230 says don't overtake snowploughs unless the lane you intend to use has been cleared.

26. It's a cold night on a country road. Which pair of clues could mean you're driving on ice?

Answer: Steering feels light and the tyres go quiet

Rule 231 says if the steering feels unresponsive, it may mean ice, and your tyres make virtually no noise when travelling on ice.

27. You're towing a small trailer for the first time. How should towing change the way you brake?

Answer: Allow more time and brake earlier

The car syllabus says that when towing you should allow more time and brake earlier when slowing down or stopping, because the extra weight needs more room to stop.

28. You're stuck behind a slow lorry on a single carriageway and want to overtake. Why should you drop back before you think about pulling out?

Answer: To get a clearer view of the road ahead

Rule 164 says getting too close to a large vehicle hides your view of the road ahead. Drop back to see further, and only overtake when you can see it's safe.

29. On a wet road you notice a rainbow-coloured film on the surface near a lorry park. Why should you take care?

Answer: Spilt diesel can make the road very slippery

Rule 227 says take extra care where spilt diesel may be on the road, as it makes the surface very slippery.

30. It's a frosty morning and you're approaching a zebra crossing. What should you allow for?

Answer: More time to stop than on a dry day

Rule 195 says at zebra crossings, allow more time for stopping on wet or icy roads.

31. How should you choose your speed on a dark, unlit road?

Answer: So you can stop well within the distance you can see is clear

Rule 126 says drive at a speed that will allow you to stop well within the distance you can see to be clear.

32. You're following a car on a fast road. How can you check you have a two-second gap?

Answer: Watch it pass a fixed point and count until you reach it

Rule 126 says allow at least a two-second gap on high-speed roads; you can check it by watching the vehicle ahead pass a landmark and counting how long it takes you to reach it.

33. You're on a busy street with parked cars, pedestrians and cyclists. What does the Highway Code advise?

Answer: Drive slowly and carefully

Rule 152 says drive slowly and carefully on streets where there are likely to be pedestrians, cyclists and parked cars.

34. What usually causes a car to skid?

Answer: Harsh braking, steering or speeding up, or going too fast

Rule 119 says skidding is usually caused by the driver braking, accelerating or steering too harshly or driving too fast for the road conditions.

35. You're driving in fog and you can only see 50 metres. Which lights may you use?

Answer: Dipped headlights, and fog lights if visibility is seriously reduced

Rule 226 says use headlights when visibility is seriously reduced, generally under 100 metres. You may also use front or rear fog lights, but switch them off when visibility improves.

36. Why do motorcycles and large vehicles need special thought when you judge following distances?

Answer: Large vehicles need more distance to stop, and you need to see past them

Rule 126 says large vehicles and motorcycles need a greater distance to stop. Staying back from large vehicles also helps you see the road ahead.

37. It's raining and the road is wet. How long should your gap to the car in front be, as a minimum?

Answer: At least four seconds

Rule 126 says the two-second gap should be at least doubled on wet roads.

38. You come over a hill and the sun is low and very bright in front of you. What should you do?

Answer: Slow down, and stop if you need to

Rule 237 says if you are dazzled by bright sunlight, slow down and if necessary stop.

39. Traffic is moving normally through a long road tunnel. What is the minimum gap you should keep to the vehicle in front?

Answer: At least a two-second gap

Rule 126 says allow at least a two-second gap on high-speed roads and in tunnels where visibility is reduced.

40. On an icy road, which gear should you use where possible?

Answer: The highest gear you can

Rule 231 says drive at a slow speed in as high a gear as possible on ice; accelerate and brake very gently.

41. You're on a motorway in heavy rain and the car ahead is throwing up spray. What should you do?

Answer: Increase your gap and use dipped headlights

Rules 226 and 227 say use headlights when visibility is reduced and keep well back; stopping distances are at least double in the wet.

42. You're driving behind a cyclist on a windy day. Why should you leave extra room when passing?

Answer: A gust could blow them sideways

Rule 232 says cyclists and motorcyclists can be blown off course by sudden gusts; allow them more room.