NASHVILLE, Tenn. (WKRN) – It’s never fun getting stuck in traffic, but what if you can make one single change with your car to prevent backups? 

Vanderbilt University researchers tested that in the middle of rush hour on Interstate 24 in Nashville, Tennessee.

We’ve all been there. You’re inching along in a traffic jam, but it’s not really clear what’s causing the slowdown. 

“There’s not a wreck. There’s not a lane merge. There’s not a car stuck in the middle of the road trying to change lanes. You’re like, ‘What happened? Why did we slow down?'” said Vanderbilt researcher Jonathan Sprinkle.

Sprinkle has a name for this bizarre phenomenon: “They’re sometimes called ‘phantom’ traffic jams.” 

His team at Vanderbilt is on a mission to stamp these out once and for all, but first, they have to understand how they happen. It turns out that drivers play a crucial role.

“The car in front of you has maybe slowed down, you slow down, you almost always slow down just a little bit more than that car, and the person behind you does the same,” Sprinkle said.

As more and more drivers hit the brake, it causes a ripple effect, essentially a phantom traffic jam, but once researchers take just a single car and flip on the automatic cruise control button to an average traffic speed, the phantom traffic jam suddenly disappears. 

“The idea with one was to say, ‘Can we just drive smoother? Will all the other cars behind us also just drive smoother?’ Sprinkle said. “And it was a revelation result that it worked pretty well.”

The automatic cruise control worked so well with just one car that researchers expanded it, testing on I-24, one of the busiest roadways in Tennessee, retrofitting 100 cars with speed and automatic cruise control, then cameras tracked the results. 

At this time, the research is being peer-reviewed, but the goal is to one day make our commutes more fuel-efficient and safer. 

“Making all these really small tweaks that have this tremendous benefit for society,” Sprinkle said.

Vanderbilt is working with several universities on this study, including Rutgers University, the University of Arizona and the University of California, Berkeley.