Following distance and stopping

Explanation

At speed you cover ground fast. The manual’s chart:

Speed	Feet traveled in one second
35 mph	51.3
55 mph	80.7
70 mph	102.7

So stay at least two to three seconds behind the vehicle ahead. To check, watch the vehicle ahead pass a fixed object (a sign or pole) and count the seconds until you pass the same object.

Many things affect how quickly you can stop: the vehicle’s weight, the type and condition of its brakes and tires, the condition and slickness of the pavement, and the grade of the road.

When the driver ahead signals a turn — or slows down and may be planning to turn — slow down and be prepared to stop.

Example

The car ahead passes a mile marker. You count “one-thousand-one, one-thousand-two” and pass it just as you say “two.” That is the minimum gap the rule allows.

Common mistake

Following closely at highway speed because “I can brake fast.” At 70 mph you travel more than 100 feet every second, so a short gap disappears almost instantly.

What the manual says

A good rule for drivers to follow is to stay at least two to three seconds behind the vehicle ahead. When following a vehicle, watch for it to pass a fixed object and estimate how much time elapses before you pass the same object.

When following a driver who has signaled an intention to make a turn, or who has slowed down and may be planning to make a turn, you should slow down and be prepared to stop.