The two-second rule is a rule of thumb by which a driver may maintain a safe following distance at any speed.

The rule is that a driver should stay at least two seconds behind any vehicle that is in front of them.  It acts as a safety buffer, allowing the following driver time to respond should anything happen.

Wait until the vehicle in front passes a fixed point on the roadway - e.g. a road sign, street light – then say “Only a fool breaks the two second rule”.  At a normal speaking rate this sentence takes approximately two seconds to say.  The front of your car should pass the same point no less than two seconds later. If the elapsed time is less than this, you should increase the distance.

The practice has been shown to reduce risk of collision, severity of an accident, and help reduce tailgating and road rage.

During adverse weather or hazardous conditions such as black ice, it is important to maintain an even greater distance of three or four seconds.

This message has been around since the 1970s – cars may have changed, but human reaction times haven’t - the original advert can be seen here…

http://www.youtube.com/watch?v=mf5d2DP4Pp0