ADI Hazard Perception Theory 1 — Questions and Answers
Question 1: In the context of hazard perception, a 'developing hazard' is defined as:
- A static hazard such as a parked car
- A potential hazard that is changing and will require the driver to take action (Correct answer)
- Any situation visible more than 100 m ahead
- An unavoidable road condition
Correct answer: A potential hazard that is changing and will require the driver to take action
A developing hazard is a situation that is actively changing (e.g. a car pulling out, a pedestrian stepping off the kerb) and which will require the driver to take action such as braking or steering.
Question 2: What is the relationship between speed and stopping distance?
- Stopping distance is directly proportional to speed
- Stopping distance increases with the square of the speed — doubling speed quadruples stopping distance (Correct answer)
- Stopping distance doubles when speed doubles
- Speed has no effect on stopping distance in good conditions
Correct answer: Stopping distance increases with the square of the speed — doubling speed quadruples stopping distance
Because kinetic energy is proportional to the square of velocity, doubling speed quadruples the kinetic energy and therefore the braking distance (though thinking distance doubles).
Question 3: Which factor has the greatest effect on a driver's reaction time?
- Tyre condition
- Alcohol, fatigue or drug use (Correct answer)
- Weather conditions
- Vehicle weight
Correct answer: Alcohol, fatigue or drug use
Alcohol, drugs (including prescribed medication) and fatigue all significantly increase reaction time; even small impairments extend thinking distance substantially at any speed.
Question 4: What technique should ADIs teach to help pupils identify emerging hazards when driving on rural roads?
- Speed up to cover the road more quickly before hazards appear
- Scan well ahead, use the road geometry to predict hidden hazards and adjust speed accordingly (Correct answer)
- Stay in the centre of the road for better visibility
- Rely on hazard warning signs to be alerted
Correct answer: Scan well ahead, use the road geometry to predict hidden hazards and adjust speed accordingly
Reading the road geometry (curves, crests, hedgerows limiting vision) and scanning far ahead allows a driver to anticipate hidden hazards and adjust speed before they develop into emergencies.
Question 5: What does 'commentary driving' help develop in learner drivers?
- Their knowledge of the Highway Code
- Their hazard perception and verbal articulation of risk identification (Correct answer)
- Their mechanical sympathy with the vehicle
- Their confidence to overtake safely
Correct answer: Their hazard perception and verbal articulation of risk identification
Commentary driving requires the pupil to narrate what they see, assess and plan, developing the habit of consciously scanning and identifying hazards and giving the ADI insight into the pupil's thought process.
Question 6: Peripheral vision is important for hazard perception because it:
- Provides the clearest detail of distant objects
- Detects movement at the edges of the field of view before it enters the area of focused attention (Correct answer)
- Is only relevant at night
- Is less affected by alcohol than central vision
Correct answer: Detects movement at the edges of the field of view before it enters the area of focused attention
Peripheral vision detects movement before the driver consciously focuses on it, providing early warning of emerging hazards from the sides such as pedestrians stepping from pavements.
ADI Hazard Perception Theory 1
In the context of hazard perception, a 'developing hazard' is defined as: