Two second rule — Tennessee Permit Test

To check your following distance, count the seconds from when the car ahead passes a fixed point, such as a sign post, until you reach it.

Guessing a gap in feet is hard at speed. Counting seconds works the same at any speed and needs no tools.

As the car ahead of you passes a stationary point on the road (a sign post, driveway, utility pole, etc.), count the seconds it takes you to reach the same spot.

If you reach the fixed point before you count 2 seconds, slow down slightly until you are following no closer than 2 seconds.

If you pass the post before you finish counting, the car ahead is too close. One hard stop and you are in its trunk.

Repeat this exercise until you are following no closer than two seconds.

In bad weather, at night, and at higher interstate speeds, increase the two-second rule to at least 4 seconds.

Wet roads take longer to stop on, and at night you see trouble later. Extra seconds make up for both.

However, during inclement weather, interstate highway driving at higher speeds and night driving, the two-second rule should be increased to allow for improved visibility.

Allow at least 4 seconds of following distance when following a motorcycle.

A motorcycle can stop faster than a car. Too close behind one, you will not stop in time.

A minimum of four seconds should allow for better reaction time and a safer space cushion under these conditions including following a motorcycle.

How do you check your following distance with the two-second rule?

Count seconds after the car ahead passes a fixed point. Guessing a gap in feet is hard at speed. Counting seconds works the same at any speed and needs no tools. Tennessee Comprehensive Driver License Manual, p.48: “As the car ahead of you passes a stationary point on the road (a sign post, driveway, utility pole, etc.), count the seconds it takes you to reach the same spot.”