How to remember Stopping Distances
TIP: Here is a great way to remember the overall stopping distances. Starting from 20mph you simply multiply the speed by intervals of 0.5, beginning with 2, for example, 2, 2.5, 3, 3.5 etc as follows:
20mph x 2 = 40 feet
30 mph x 2.5 = 75 feet
40 mph x 3 = 120 feet
50 mph x 3.5 = 175 feet
60 mph x 4 = 240 feet
70 mph x 4.5 = 315 feet
The above calculations are a simple way to help you remember the correct stopping distances, but please be aware that these are approximate. The overall stopping distance is really the only safe separation gap, anything less than this can be considered a risk.