Safety Margins Theory Test 2021
The Safety Margins Theory Test consists of 44 questions.
You need 38 out of 44 (86%) to pass. There is no time limit for this test.
Click here to read our Safety Margins Theory Test revision notes.
Weather and General Issues
Hot Weather, Fog and Wind
- Hot weather can cause the road surface to soften, affecting tyre grip and braking
- In foggy conditions always use dipped headlights, slow down, allow more time for your journey and increase the gap to the vehicle in front of you
- Side winds are most likely to occur on an open road and you should take care when passing cyclists and motorbikes, giving them extra room.
- The braking distance is at least twice as normal in wet weather, and the four second rule should be adhered to
- Heavy rain can make the steering feel lighter, and you should ease off the accelerator to avoid the risk of aquaplaning
- Driving through deep water may affect your brakes, and you should dry them off by going slowly and applying them gently
- Dipped headlights should be used in the case of motorway spray during heavy rain
- Before starting a journey, you must clear any ice or snow from windows, mirrors, lights and number plates
- When driving off in snow, you should use the highest gear you can to prevent the wheels from spinning
- The braking distance on ice is at least ten times longer than normal, and you should brake gently and in plenty of time
- If approaching a sharp bend in snowy conditions, you should slow down and avoid sudden steering movements
- If the steering suddenly feels light, this could be an indication of black ice on the road, and you should ease off the accelerator
General Safety Issues
- When approaching a right hand bend, you should keep well to the left to improve your view of the road ahead
- Be aware that coasting i.e. travelling long distances in neutral, reduces driver control
- When driving down a steep hill, select a lower gear and use your brakes carefully to control your speed
- When parking facing downhill, you should turn the wheels towards the kerb and apply the handbrake
- The most common cause of skidding is known to be driver error
Stopping Distances and Brakes
The definition of the overall stopping distance is the combination of thinking and braking.
- 20 mph – Thinking 6m + Braking 6m = 12m
- 30 mph – Thinking 9m + Braking 14m = 23m
- 40 mph – Thinking 12m + Braking 24m = 36m
- 50 mph – Thinking 15m + Braking 38m = 53m
- 60 mph – Thinking 18m + Braking 55m = 73m
- 70 mph – Thinking 21m + Braking 75m = 96m
- Reduce speed
- Select the appropriate lane in plenty of time
- Keep the correct separation distance
- They are of most use when stopping quickly in an emergency
- They permit the vehicle to be steered when braking hard
- The anti-lock system begins to work after you have applied maximum brake pressure, just before the wheels lock
- As they prevent the wheels from locking, you are less likely to skid when emergency braking
- Proper use requires you to brake rapidly and firmly until you have stopped or slowed down
Safety Margins Theory Test Tips
There is no option other than to learn the stopping distances off by heart, using the principle that the faster you are travelling, the further it takes you to stop. There may be questions about anti-lock braking systems, and you should have some knowledge as to how they work.