Four cars travel too close to each other — an esitmated one second apart — this summer on state Route 3 at Indian Carry Road. (Provided photo — Dan Jenkins)

The Insurance Institute for Highway Safety previously reported that 40% of all automobile crashes involve tailgating — or, more formally, following too closely.

What driver hasn’t been annoyed by the driver behind riding right on his/her tail? Answer: no one! But the flip side is how many of you, as drivers, are guilty of this practice? Answer, nearly everyone, at least sometimes.

Vehicle and Traffic Law Section 1129 requires drivers to not follow another vehicle more closely than is “reasonable and prudent,” having due regard for the speed of such vehicles, the amount of traffic and the condition of the highway. So what is reasonable? Traffic experts recommend that you keep at least THREE SECONDS between you and the car in front. When you see the vehicle in front of you pass a stationary object, such as a utility pole or sign, count to three seconds, and if you arrive at the same object before you get to three seconds, you are too close — drop back. Three seconds is the recommended spacing under good driving conditions. When conditions deteriorate because of weather, darkness, fatigue, etc., more spacing is required.

Take a look at the picture that accompanies this article. The photo was taken this summer at the Coreys crossroads intersection on state Route 3 in the town of Harrietstown and sent to me by a reader. Route 3 is a 55 mph highway with numerous curves. The photo clearly shows a line of four cars traveling much too close to each other. The reader estimated these cars were about one second apart.

In early July, a crash occurred at this intersection when car A was westbound on Route 3, stopped, waiting for a break in oncoming traffic to turn left onto the Coreys-Axton road. Car B also stopped behind car A, but car C could not stop in time and went off the right shoulder, crossing the Indian Carry Road and into the ditch, hitting a tree. Had a car been waiting to enter Route 3 from the Indian Carry Road. like the one in the photo, it would have been T-boned by the car that went into the ditch.

Years ago when I learned to drive, the rule of thumb was to keep one car length for every 10 mph that you were driving. That is no longer taught. The current advice is to keep at least three seconds behind the vehicle you are following, in good weather and road conditions. The three-second rule works at any speed. In poor driving conditions, more time is recommended. Of interest, in the Pennsylvania driver’s manual it is recommended to stay four seconds behind even in good conditions.

The one takeaway from this column is to be aware of how closely you are following the vehicle in front of you. If you are in a no-passing zone, stay well behind the car in front until you get to a place where passing is allowed and is safe to do so. By tailgating, you significantly increase the risk of a crash. Furthermore, you won’t get to where you intend to go any faster, and you will likely irritate the other driver. Play it safe, and keep a proper distance.