Keeping a safe following distance is a simple thing drivers can do to keep themselves safer on the road.
Rear-end collisions caused by following too closely are some of the most common collisions on freeways and also residential streets. They are also some of the most preventable.
The US Dept of Transportation describes following too closely as “situations in which one vehicle is following another vehicle so closely that even if the following driver is attentive to the actions of the vehicle ahead, he/she could not avoid a collision in the circumstances when the driver in front brakes suddenly.”
The cost of these collisions goes far beyond auto repair. Neck injuries in these collisions cost almost 9 billion dollars in insurance claims. About 25% of the total payout for crash injuries.
HOW TO CALCULATE SECONDS
Measuring following distance in seconds is a simple thing.
And it’s more accurate than counting “car lengths” like we were taught in drivers ed back in the 80s. Cars come in various sizes, and even if there were a standard size for car length, not everyone is equally good at estimating distances.
No, basing your following distance on seconds is much more accurate and much, much easier.
Simply watch the car in front of you as it passes some inanimate object beside the road: a sign post, a street light, any fixed object will do. Once the car passes this object, begin counting the seconds — 1 one thousand, 2 one thousand, etc. — until your car passes the same object.
Then you’ll have a fairly accurate measure of your following distance in seconds.
2-SECOND RULE BUT…
Most drivers have heard of the “Two Second Rule” for following distance. But choosing a safe following distance is more complicated than that.
What following distance is safe depends on the speed of traffic and on driving conditions.
At higher speeds or on wet pavement, your brakes will take longer to bring your car to a stop, so the faster you’re going the more following distance you need.
The chart below explains how to determine your safe following distance for various speeds and road conditions pretty well.
WHY SO MUCH FOLLOWING DISTANCE?
Following distance is based on how much time it takes to stop your car, and how much distance your car will cover while it stopping.
Many drivers don’t realize the distance needed to be safe. At 70 mph, we cover about 100 feet per second. It take the average driver about 3/4 of a second to realize they should apply the brakes and another 3/4 of a second to apply them. At 70 mph you have gone 150 feet. The breaking distance is over 300 feet. Total stopping distance over 400 feet. Even at a following distance of 50ft, you could not stop in time.
And if you hit someone from behind, it is your fault.
There are practical and easy steps that can be taken to avoid collisions caused by too little following distance.
- Always keep a safe following distance yourself, and avoid other drivers who follow too closely. Soon or later they’ll wind up in a crash, and you don’t want their problems to become yours.
- At a stop light leave at least one car length between yourself and the car in front of you. When driving in a residential area, always leave 2-3 seconds of following distance between you and any vehicle in front of you. At free way speeds at least 4-6 seconds.
- Always be prepared for the car in front of you to stop suddenly.
- When going around turns, remember that the car in front of you may brake slightly to make the turn. Be prepared for this and increase your following distance as you approach a turn.
DON’T WORRY ABOUT TAILGATERS.
As a driver, you can control the following distance between you and the cars in front of you.
But what about the cars behind you? How do you keep tailgaters from following too close on your bumper?
Simple: slow down and let them go around you. Most people tailgate because they’re in a hurry. If you slow them down even more AND give them a chance to pass you, they will.