Tailgating Officially Makes Traffic Worse, Jerks

Tailgating Officially Makes Traffic Worse, Jerks
To sign up for our daily newsletter covering the latest news, hacks and reviews, head HERE. For a running feed of all our stories, follow us on Twitter HERE. Or you can bookmark the Lifehacker Australia homepage to visit whenever you need a fix.

If you’ve ever encountered a “phantom traffic jam” or traffic slowdown that doesn’t seem to have an apparent cause, it was probably some jackwagon tailgating somebody. Researchers at MIT found that not only does tailgating not get you anywhere faster, it actually creates traffic jams that shouldn’t exist.

Photo by Leeann Cafferata.

Tailgating, or the act of driving so closely behind someone you could write “wash me” in the dirt on their rear window, has always been rude (not to mention unsafe). At best the car in front of you will speed up a little in fear of being road rage murdered, but more than likely you’ll just look like an impatient jerk.

And what’s worse is you’re making things less convenient for yourself and every other driver in your lane, says MIT professor Berthold Horn and postdoctoral associate Liang Wang. In order for traffic to keep moving smoothly, Horn says cars need to be evenly spaced on the road:

“Our work shows that, if drivers all keep an equal distance between the cars on either side of them [front and back], such ‘perturbations’ would disappear as they travel down a line of traffic, rather than amplify to create a traffic jam…”

Here’s a nifty animated graphic to explain what happens:



Basically, when you tailgate, you remove your ability to slow down gradually in the event a car up ahead reduces its speed. Because you have less time to react and avoid rear-ending the car in front of you, you hit the brakes hard and take away all of your vehicle’s momentum in an instant.

All the cars behind you then have to slow down quickly as well while you build up speed again. It causes a chain reaction that eventually brings traffic to a crawl — or causes accidents — for no good reason.

Of course, Horn and Wang are very aware people aren’t going to stop tailgating or pay more attention to the space between themselves and other vehicles, so they hope adding features to future vehicles can fix the problem. By implementing what they call “bilateral control” into adaptive cruise-control systems, phantom traffic jams may become a thing of the past.

They estimate drivers may even be able to get somewhere nearly twice as fast. Until then, give yourself plenty of space between you and the car ahead as best you can. It benefits everybody on the road.

Improving traffic — by tailgating less [MIT]


  • “give yourself plenty of space between you and the car ahead as best you can.” and in Sydney someone will overtake you via the parking lane and insert themselves into that gap.
    Also, when you pause before lights to avoid blocking the entrance to a side-street: some car will then go around you to sit across the entrance and block turning traffic.

    • Both are f**ing annoying and common in Melbourne also. You’re going along at the speed limit on the freeway. Driving with a safe distance and people speed up, come in front of you forcing you to then slow down when they immediately slow back towards the speed limit.
      Those people go to the special kind of hell.

  • The bad news: these jerks don’t care.

    Until we get self driving cars and the last Mitsubishi ute is torn from the hands of a tradie, this will continue.
    (Or until police enforce existing laws, but let’s face it that will never happen).

  • I feel safer with adaptive cruise control because my speed is controlled by a machine and I don’t feel pressured by the guy behind me.
    In my old car, I felt obliged to go slightly faster because of the perceived pressure from the car behind me.
    Most times the following car retains their speed so it’s just me being paranoid. The adaptive cruise control takes that paranoia away.

Show more comments

Comments are closed.

Log in to comment on this story!