If the car in front of you stops suddenly, you need to be far enough behind it so that you can stop in time to avoid a collision.  But how far is that?  Your safe following distance depends on how fast you are going and what the road conditions are.  The two-second rule is a convenient way to figure your safe following distance at various speeds without having to do calculations with numbers.

 The Two-Second Rule says that your following distance should be at least two seconds travel time behind the vehicle in front of you.  Measure your following distance this way:  Choose a landmark such as a telephone pole or tree that the vehicle in front of you has not yet passed.  When the vehicle’s rear bumper passes that landmark, start counting seconds: “One thousand and one, one thousand and two.”  If your front bumper reaches the landmark before you finish counting, you are following too closely.

Use the Two-Second Rule to check your following distance from time to time when you are on the road.  By doing this, you will learn to automatically maintain a safe following distance in all conditions.