Safe Following Distance: Follow the 3 Second Rule

by | Sep 26, 2020 | Defensive Driving


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Safe Following Distances and the Three Second Rule

Just the act of driving carries some degree of risk, but when your following distance is too close to other vehicles, the odds of getting into an accident increase by quite a bit.

In order to avoid collisions, keeping a safe following distance and using the 3-second rule can help you stay safe whenever you’re behind the wheel.

Read on to learn more about the importance of maintaining a good distance and details about how you can put it into practice every time you drive.

Stopping Distance and Your Safety

To understand the importance of maintaining a safe following distance, you need to understand the basics of stopping distance. The term stopping distance means how far it takes for your car to come to a full stop in an emergency.

The stopping distance uses two major factors to determine the actual distance required. First, your reaction distance to the other vehicle and second, your braking distance.



The reaction distance is determined by how far your car is between something happening ahead of you and how you react to it. There is always a certain amount of time between the moment something occurs and when you actually hit the brakes. Reaction distances can be as short as a millisecond or they could be several seconds long!

How long the reaction time or distance is can depend on a range of factors. Things like your age, your driving experience, and even weather conditions can all come into play. In most cases, it can take anywhere from 0.2 seconds to two full seconds before you react and come to a stop.

Drivers who are speeding will have a shorter reaction distance since they’ll run into trouble at a much faster pace. The braking distance is also a crucial part of this equation. This term refers to how far your vehicle travels after you’ve hit the brakes and come to a complete stop.

A Simple Equation

The faster you’re driving, the longer it will take for you to stop. Your braking distance is directly related to your speed. For example, if you were to double your speed, you’d quadruple the braking distance.

With these factors combined, your stopping distance is equal to your reaction distance plus your braking distance. If an emergency happens ahead of you and you drive another 20 feet before reacting to the incident and another 20 feet before you stop, the total stopping distance is 40 feet.

To avoid an unexpected collision, you’ll need to maintain a safe following distance. Putting the 3-second rule into place can help make this easier and keep you from getting involved in an automobile accident.

States with Most Tailgating Violations

Tailgating creates some of the most dangerous situations on the road. Some drivers forget the laws of the road—and the law of physics—and put themselves and every driver around them in danger by driving close to other vehicles.

Based on insurance company reports, these are the top 10 states with the most tailgating violations:

10. Colorado

9. New Hampshire

8. Ohio

7. Connecticut

6. Washington

5. Virginia

4. Utah

3. Nebraska

2. Georgia

1. Idaho

Many of these states also rank high on the list for aggressive drivers. Following too closely is considered a form of aggressive driving. While it’s important to be aware of the cars in front of you, you should also be aware of vehicles behind you.

If a driver behind you is tailgating, you leave additional space between your vehicle and the car in front of you to make sure you have enough time to slow down and avoid both front and rear collisions.

So, What is a Safe Following Distance?

Ideally, you should always try to maintain a 3-second following distance or more whenever possible. This will give you more time to react in case the vehicle in front of you slams on the brakes or hits another car.

You never know when debris could be in the road, construction is ahead, or there’s another accident that has already occurred. Giving yourself the distance you need to avoid hitting someone else can be the difference between a horrible day on the road and a safe one.

While the 3-second rule should be the basic principle of using a safe following distance, the amount of time you need to react could be longer. This is especially true if you’re driving in inclement weather, the roads are icy, or you’re driving at night.

Another thing that can affect your following distance is the type of vehicles on the road. For example, you should stay at least 70 feet or five car lengths away from a snowplow.

For other standard cars, try to stay around 243 feet or about 16 car lengths away whenever you can. Of course, heavy traffic and busy roads don’t always make this possible but this is the best space to ensure you can stop safely.

If you’re driving alongside semi-trucks, try to stay about 300 feet or 20 car lengths back. These huge trucks carry heavy loads and if they slam on their brakes, the load could come loose and cause a very serious accident.

When it comes to emergency vehicles like fire trucks, ambulances, and police vehicles with their lights and sirens on, stay approximately 500 feet or 33 car lengths back. These vehicles are typically speeding to get to their destination, so you don’t want to get in the way of them doing their job.

How to Understand and Calculate the 3-Second Rule

Rear-end collisions are the most common type of accident, and it’s usually because at least one driver is not paying attention. This results in a slower reaction, which reduces the braking and stopping distance.

When you follow the 3-second rule, you’ll always stay focused on the car or truck in front of you. Give more space for larger vehicles, and do your best to avoid distractions so you’re not involved in a possibly dangerous collision.

Calculating this rule is fairly simple. Basically, you should always allow three full seconds between yourself and the vehicle in front of you. You can do this by using a specific point ahead such as a sign that you see on the side of the road, and then count “one-thousand-one, one-thousand- two, one-thousand-three.”

If you find that you’ve passed the marker point before you finish counting the three seconds, you are following the other vehicle too closely. This simple rule works no matter what speed you’re traveling at. That’s because the faster you travel, the longer the distance you cover within the three-second time frame.

If your speed increases, the distance between your vehicle and the car in front of you also needs to increase in order to leave the three-second gap. Besides the speed that you’re driving, the 3-second rule also considers that the other car in front of you needs a certain distance to come to a full stop. The rule gives you just a little extra time in case they hit their brakes unexpectedly.

Of course, there are certain situations that may require you to adjust your following distance. For example, if you are pulling a large trailer, you will need additional time and space to stop the extra weight you’re moving.

Also, you should give yourself a bit more distance when following a motorcycle. Since they are smaller and can stop fairly suddenly,  you need to provide enough space for you to react and bring your vehicle to a stop to avoid a collision

Regardless of your speed, the weather conditions, and other factors, using the 3-second rule is an excellent way to ensure that you’re always maintaining a safe following distance. Do your best to practice it every time you drive and it will become second nature as you use it more frequently.

Even just an extra second can provide you with valuable time to react and avoid a collision. By using the 3-second rule, you’ll have a constant safety net out on the road.

When to Increase Your Following Distance

There may be times when you’ll need to increase your following distance to keep you safe. If a tailgater is behind you, allow some extra space between your vehicle and the one in front of you, and avoid sudden braking. To avoid the tailgater, merge into another lane if possible.

If the roads are slippery, you can increase your following distance by counting to a higher number. Always watch your speed and following distance when driving in weather conditions like rain, snow, or ice.

Be especially vigilant when following motorcycles or bikes on wet or icy roads, gravel, and metal surfaces. Motorcyclists and bicyclists are at high risk of falling on these types of surfaces. If you’re too close behind them, it could result in disaster.

If the driver behind you wants to pass, allow a little extra room in front of your vehicle. This room gives the other driver the space they need to move in front of you, and it keeps you at a safe distance from the other vehicles on the road, too.

When behind a trailer or any vehicle towing a heavy load, increase your following distance as much as possible. The extra weight of these vehicles and the loads they carry can make it more difficult for them to stop. This also applies whenever you are following a large vehicle that blocks your view ahead so you’ll have more space to see around it.

You should also increase your following distance whenever you see any type of bus if you’re driving in the cities. These vehicles must stop at railroad crossings, so stay vigilant.

And finally, pay close attention to your following distance whenever you merge onto the freeway. Merging into fast-moving traffic can be dangerous if you don’t have a safe distance between yourself and other vehicles.

Follow the Rule for Safe Driving

When you maintain a proper following distance and follow the 3-second rule, you’ll have a much better chance at avoiding a serious collision. Always ensure that you have enough time to react and brake so that you can avoid hitting a vehicle on the road.

Visit our website if you’ve received an auto insurance rate increase, a traffic ticket, or need to take a court-ordered defensive driving course to enroll in our online defensive driving courses today!

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