The above stopping distances are under normal circumstances, that is… good road condition and the vehicle’s brakes are in good working order.
Reaction time was based on 1 second. Depending on the conditions and the situation, it might differ. At night the reaction time can increase to 1.5 seconds.
The first column indicates the distance that was travelled during the reaction time, and the second column is the distance that was travelled after activating the brakes.
To calculate distance travelled the following formula can be used:
40km/h * .278 = 11.12m/s