Following Distance: The “3 Second Rule”
One of the most common errors I address on driving lessons is “tailgating,” following too close. If I ask the student what the proper following distance is, they often respond with the wrong answer. “Two car lengths” is very common. I tell them they just crashed because that car in front stopped quickly and they did not have time to react. When I ask them if the “3 Second Rule” sounds familiar, they usually say “oh, yeah” or similar response, but, they do not know how to implement it. Space is time, and time is your friend.
What is the “3 Second Rule?” It is the MINIMUM distance we should maintain behind the car we are following. Students will often get that correct on the written test, but then have trouble putting it to practice on the road. It really is very simple. When the vehicle in front of you passes an identifiable, fixed point start counting. “One-thousand one,…one-thousand two,…one thousand three.” Put half a beat between each one. You should reach one-thousand three at or BEFORE the point where you started counting. You can check your accuracy with a clock that has a second hand and compare your counting to the actual seconds.
What we use as a starting point is not important as long as we can see it and tell when the car ahead passes it. Shadows work very well because they are easy to identify and tell when the car passes them. Over passes, shade from trees, buildings or other things are very useful. Changes in pavement that can be seen from a distance, lines across the road, arrows or speed limits painted on the road all work well. A point where two painted lines on the highway come together, a pile of trash alongside the road, where skid marks begin or end. This time of the year the sun is always at an angle, causing the vehicle ahead of us to throw a shadow and that can be used as a “pointer,” pointing at a sign or other landmark. These are all easy to see and use as our starting point.
Tailgating is a common contributing factor in new driver collisions. It can, of course, cause a rear end collision but also may cause a loss of control collision as the new driver tries to avoid hitting the car in front of them. It is important to work with your student driver to practice safe following distances in varied situations. Have your student driver set what they think is a three second following distance and have them count it out loud. Remember, normal speaking cadence with a half a beat between each one. Adjust the distance as necessary by just slowing slightly, two or three miles per hour is all it takes in most situations, let the car in front pull ahead until the “3 Second Rule” space is established or reestablished. Space is time, and time is your friend.
I had a student who consistently followed too close. This student knew the three second rule so I had them count it out. The student counted so fast, it was difficult to understand. They were counting that fast to get to three before reaching the point they started counting. This is not the proper way and the student was actually about one second behind the car they were following.
The benefit of using time as a guide is that it adjusts for speed. The faster you are traveling, the bigger the gap and the more time you have to perceive, react, and stop or otherwise avoid hitting the hazard. A three second gap between your car and the one in front will appear HUGE when compared to other cars on the road. That is because very few drivers are maintaining the proper and SAFE following distance. They are apparently willing to jeopardize their safety and that of others on the road to arrive at their destination two to five SECONDS sooner. It may actually take them a couple hours longer after they deal with the crash, if not several weeks of recuperation from injuries received in the crash. Is a few seconds really worth the risk? I don’t think so.
The California Driver Handbook recommends more than a three second following distance in some circumstances. It advises a “4 or more” second following distance when: being crowded by a tailgater, driving on slippery roads, following motorcycles, the driver behind wants to pass, towing a trailer or carrying a heavy load, following large vehicles that block your view like a semi, or you see a vehicle that must stop at railroad crossings. I advise emphasis on the “more“ part. More is better, in all situations, especially for new drivers because they are still learning to recognize hazards as they develop skills and experience, and may need more time to perceive the danger and react.
Leaving more distance between your car when following a large vehicle that blocks your view allows you to see around that vehicle. You can see changes in traffic conditions sooner and, have more space and time to react and adjust. The vehicle ahead of you may see a hazard that they need to avoid, but wait until it is safe, or sometimes the last minute, to avoid it. If you are following those vehicles too closely, you will not have time to react when they move out of your way to avoid that hazard they have blocked from view.
Motorcycles can stop shorter than cars in most situations and, because they have two wheels they can go down. We should give them more space so we can avoid running over them in those situations, which will ruin their day, and yours. If we are towing a trailer, we have less control and need more space to stop. The same applies to hauling a heavy load in a truck or SUV. Slippery roads, from water, dirt, snow, ice and other debris, does not give our tires the friction coefficient that a dry, clean road will, so we need more space and time to stop under those conditions. Space is time, and time is your friend.
Tailgaters are difficult to deal with but if we increase OUR following distance we minimize the hazard. I ask my students what is the danger of a tailgater. They usually respond correctly, that if I have to stop quickly they will hit me. The Driver Handbook suggests slowing down for a tailgater, changing lanes, or pulling off the road and let them pass. All good techniques, but I recommend and always go to an increased following distance first, which does require slowing down slightly, then look at the other options. By increasing our following distance to SIX or MORE seconds, we give ourselves more space and time to slow down gradually, we don’t have to stop suddenly and we also have time to look for an “out.” Where can I go to avoid being hit from behind? I have seen many tailgating crashes that could have been avoided if one of the drivers had driven onto the ten foot, or wider, shoulder or into the center dividing strip of land. Work with your teen driver and practice the “3 Second Rule” every time you go for a drive. It will give your teen a safety factor if they delay in reacting, are distracted for a brief time like changing a CD or radio station. We drive by habit and need to develop good, safe practice driving habits. SPACE IS TIME AND TIME IS YOUR FRIEND.
