How close are you to that vehicle in front of you as you drive down the road? Would you have enough time to slow down if the other vehicle suddenly braked? Your answers depend on many factors.
You may have learned in drivers’ education class to allow for one car length between you and another vehicle for every ten miles of speed you are traveling. This is great advice for private passenger vehicles and light trucks, but it can be difficult to calculate.
Three second rule
An easier rule of thumb for a following distance is the three-second rule. Pick a fixed object on or near the road, such as a road sign or lane stripe. Once the lead vehicle passes the object, start counting one-thousand-one, one-thousand-two, one-thousand-three. If you reach that fixed object before you’ve said one-thousand-three, you are following too closely.
Driving commercial vehicles
Commercial vehicles like large trucks take longer to stop and should have an even farther following distance. If you’re driving a larger vehicle and your speed is less than 40 mph, the rule of seconds suggests that you allow at least one second for each 10 feet of your vehicle length. For speeds of more than 40 mph, add another second to the total time.
Likewise, the next time you pass a large truck and get in front of it, ask yourself if you’re giving the trucker enough space to stop in an emergency. You may still be able to stop suddenly, but will the trucker be able to stop before he or she strikes the back of your vehicle? If you’ve encroached in their following distance, the odds may not be in your favor.
The suggested distances apply during favorable weather and road conditions. Driving through rain, fog, heavy traffic, or on poor pavement will require even more time to stop in an emergency.
Tailgating can be seen as aggressive behavior by other drivers and can lead to road rage incidents. Saving a few seconds during your trip isn’t worth increasing your chances of being involved in a collision. Even a minor fender-bender will be an inconvenience to all of the parties involved, and the repairs could be expensive and time consuming. An incident involving a fatality is life-altering to many people, including loved ones. Being late to an appointment beats not making it there at all. If someone is tailgating you, focus on maintaining your proper speed so you remain in control of your vehicle.
Driving is a privilege, not a right. Driving safely is everyone’s responsibility, and maintaining an adequate following distance helps to ensure everyone’s safety.