Is it a 2, 3 or 4-second rule for following on a highway?

The in basket: I was cleaning out old e-mails when I came across one from Donald Payne, sent in 2008, to which I’d never attended.

“Yesterday I was signing up a senior driver for an AARP Senior Driver Class,” Don said, “and she said she had seen a program on TV in which two

Washington State Patrolmen were discussing, explaining and advocating a two-second following distance.  I saw the program myself, earlier, and

that’s what they were dealing with — a two-second distance.  “The lady said she was confused.  She is aware that the

State Driver’s Guide says four seconds; and having taken our class previously, she is aware of the three-second recommendation.

“So, the lady’s question is:  Which one is right?  Is it two, three, or four?

“What’s your take on the situation?”

The out basket: One of the troopers in question, Johnny Alexander, said he and Monica Alexander “may have briefly mentioned following distance during the KOMO Traffic Reports more than three-years ago. (That would have been around 2005.)

“However, we never participated in a television program where following distance was the topic,” he said. “The Department of Licensing Drivers Guide, page 71 – “Space Ahead,” indicates if you are driving 30 mph or less, the two-  to three-second rule is recommended.  However, at speeds higher than 30 mph, the four-second rule is recommended.  The Washington State Drivers Guide can be accessed through

“We encourage our troopers to use the four-second rule.  Most troopers add one-second to the count to further reduce the chance of being the causing driver of a rear-end collision,” he said.

Since Don asked, my take on the situation is you’ll be darn lucky to maintain the recommended distance from the car ahead on a multi-lane highway in heavy traffic as some other driver will probably slide into the space, but it’s worth a try. It should be easily observed on a two-lane highway.

And in case this whole idea is foreign to you, here is how the driver’s guide says it works:

• Watch when the rear of the vehicle ahead passes a sign, pole, or any other stationary point.

• Count the seconds it takes you to reach the same spot: one-one-thousand, two-one-thousand, three-one- thousand, four-one-thousand. You are following too closely if you pass the mark before you finish counting.

• If so, drop back and then count again at another spot to check the new following distance. Repeat until you are following no closer than four seconds.

6 thoughts on “Is it a 2, 3 or 4-second rule for following on a highway?

  1. I was always taught it’s the “Two potato” rule. “One potato, two potato”.

    Seriously, if you tried to leave four seconds on the freeway during rush hour you’d never get where you’re going because people would be shaking their fists and cutting you off the whole way home.

    Another way I was taught was one car length per 10 miles per hour. The distance between dashed lines in the road is about a car length.

    Here is another question for you, how much distance should you leave between you and the car in front of you at stop light or sign? I was taught that you should be able to see the rear tires touch the ground on the car in front of you. But once again with busy roads and short turn lanes, this is not always the most polite thing to do when others are trying to squeeze into the lane.

    Thanks for the opportunity to share.

  2. I’ve followed the three second rule for yes years. surprisingly no one usually fills in the space. Even in rush hour traffic. sure maybe a few cars slip in every now and then but I have open ed up 50 yards in front of me quite frequently during rush hour. research the affects of adaptive cruise control sometime it’s quite an amazing technology that could reduce rush hour impact around the region

  3. The 4 second rule at 60 MPH equates to 352 feet or just 8 feet less than the goal post to goal post length of a football field. At 30 MPH we should stay a half a field apart and at 40 MPH 2/3’s of a field. I find these tools more useful than counting.

  4. It doesn’t give me the answer to the driving test. Some places they say three seconds and some places in the DMV book they say two seconds

  5. It’s safer to drive fast with adequate distance than slower all bunched up! So many drive as if they’ve never heard of the 3 second rule. Another thing it does is allow safe merging, where the rest car can back off a little and you have the 3 second room again.
    One day, I saw smile coming from the lead car, then more smoke from those behind him, where everyone was locking up. They all collided. I swerved off an exit, as if I recall, I had cars behind me or didn’t have time to check. Similiar situation happened to a friend. He stopped adequately, but was rear ended by another that drove him into the cars collided in front of him.
    Which, there’s always the possibility of getting severely hurt. Which any number will snear at, but when it happens, wishing back doesn’t change the results.
    I’ve had plenty of courteous drivers where they keep a healthy distance, where it feels safe. But I don’t understand others that follow close, as it won’t get them anywhere faster.
    But there are those places where others will zoom in front of a person, then someone else, which might be why some keep tighter distances???
    You know flying an airplane, there’s much more space between vehicles, lol.

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