Hazard Perception Theory Flashcards

In the context of hazard perception, a 'developing hazard' is defined as:

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.

What is the relationship between speed and stopping distance?

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).

Which factor has the greatest effect on a driver's reaction time?

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.

What technique should ADIs teach to help pupils identify emerging hazards when driving on rural roads?

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.

What does 'commentary driving' help develop in learner drivers?

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.

Peripheral vision is important for hazard perception because it:

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.