ADI Hazard Perception Theory 2 — Questions and Answers
Question 1: The stopping distance at 70 mph in dry conditions is approximately:
- 53 m (175 ft)
- 75 m (245 ft) (Correct answer)
- 96 m (315 ft)
- 120 m (394 ft)
Correct answer: 75 m (245 ft)
At 70 mph the total stopping distance is approximately 96 m (315 ft), comprising 21 m thinking distance and 75 m braking distance — the length of more than six car lengths.
Question 2: Which situation at a junction requires an ADI to teach the concept of 'effective observation'?
- Turning left into a clear road
- Emerging onto a major road with restricted sight lines — look, assess, look again and move only when safe (Correct answer)
- Driving straight over a mini-roundabout
- Exiting a motorway at a clearly signed junction
Correct answer: Emerging onto a major road with restricted sight lines — look, assess, look again and move only when safe
Effective observation at restricted junctions involves looking right, left and right again (and for one-way roads, left-right-left), reassessing continuously before committing to the manoeuvre.
Question 3: What makes the crest of a hill particularly hazardous from a hazard perception standpoint?
- The road surface is always wet at the top
- Oncoming vehicles and pedestrians are hidden beyond the crest, requiring reduced speed to a safe stopping distance (Correct answer)
- The road always narrows at a hill crest
- Traffic always merges at a hill crest
Correct answer: Oncoming vehicles and pedestrians are hidden beyond the crest, requiring reduced speed to a safe stopping distance
A hill crest cuts off the driver's view of the road ahead; hazards on the other side may not be visible until very close, requiring speed to be reduced so the driver can stop within the distance they can see to be clear.
Question 4: In hazard perception theory, a 'latent hazard' differs from a developing hazard in that:
- It has already caused a collision
- It is a situation that has potential to develop into a hazard but has not yet done so (Correct answer)
- It only applies to pedestrian situations
- It is a fixed feature of the road
Correct answer: It is a situation that has potential to develop into a hazard but has not yet done so
A latent (or potential) hazard is a situation that could develop — such as a ball bouncing near the road or a parked van obscuring a junction — requiring monitoring but not yet demanding action.
Question 5: How does tiredness affect hazard perception and what should a driver do?
- Tiredness improves concentration through adrenalin
- Tiredness slows cognitive processing and reduces the ability to detect and respond to hazards; the only cure is sleep (Correct answer)
- A radio and an open window restore full alertness for the journey
- A 5-minute break every 4 hours is sufficient
Correct answer: Tiredness slows cognitive processing and reduces the ability to detect and respond to hazards; the only cure is sleep
Fatigue impairs attention, slows reaction time and reduces hazard detection ability; opening a window or turning on the radio provides only minutes of relief; the only real remedy is stopping and sleeping.
Question 6: When following a vehicle at night, why is it important not to over-drive your headlights?
- Bright headlights dazzle the car in front
- The driver must be able to stop within the distance illuminated by their headlights (Correct answer)
- Full beams must be used within 200 m of a vehicle ahead
- Headlights reduce fuel efficiency at night
Correct answer: The driver must be able to stop within the distance illuminated by their headlights
Driving faster than can be stopped within the lit area means the driver cannot stop in time for hazards at the edge of their light reach — a form of excessive speed for the conditions.
ADI Hazard Perception Theory 2
The stopping distance at 70 mph in dry conditions is approximately: