What is perception time?

Perception time is the time to see a situation and understand that you must stop. It is about three-quarters of a second, and longer for new drivers. Reaction time comes next: the time to move your foot from the gas pedal to the brake pedal.

Source: Driver’s Guide: Cars and Light Trucks (Government of Alberta, Spring 2026), Stopping time and distance, page 51

Practice question

A driver sees a danger and understands that stopping is necessary. What is this period of time called?

1. 1Reaction time
2. 2Braking time
3. 3Following time
4. 4Perception time