Autonomous cars may help reduce the amount of gridlock in city highways and roads.

According to a new study conducted by researchers from several universities, autonomous vehicles may be crucial in alleviating traffic problems plaguing many metropolitan areas by reducing the amount of traffic caused by stop-and-go traffic.

“Our experiments show that with as few as 5 percent of vehicles being automated and carefully controlled, we can eliminate stop-and-go waves caused by human driving behavior,” Daniel Work, assistant professor at the University of Illinois at Urbana-Champaign and a lead researcher in the study, said in a statement.

According to Work, the use of self-driving cars will one day lead to the replacement of classical freeway traffic control concepts including variable speed limits.

However, Work said for this theory to prove true a deeper understanding of the dynamic between autonomous vehicles and the human drivers is necessary.

During field experiments conducted in Tucson, the researchers had a single autonomous vehicle circle a track continuously with at least 20 other human-driven cars.

This revealed that under normal conditions humans naturally create stop-and-go traffic called a “phantom traffic jam,” even without bottlenecks, lane changes, merges or other disruptions.

 However, by controlling the pace of the autonomous car, the researchers were able to smooth out the traffic flow for all the cars, showing that even a small percentage of autonomous vehicles can have a significant benefit to traffic flow.

“Before we carried out these experiments, I did not know how straightforward it could be to positively affect the flow of traffic,” Jonathan Sprinkle, the Litton Industries John M. Leonis Distinguished Associate Professor in Electrical and Computer Engineering at the University of Arizona, said in a statement. “I assumed we would need sophisticated control techniques, but what we showed was that controllers which are staples of undergraduate control theory will do the trick.”

Benedetto Piccoli, the Joseph and Loretta Lopez Chair Professor of Mathematics at Rutgers University, explained that there are still some hurdles before autonomous vehicles can be unleashed on the highways.

“Fully autonomous vehicles in common traffic may be still far away in the future due to many technological, market and policy constraints,” Piccoli said in a statement. “However, increased communication among vehicles and increased levels of autonomy in human-driven vehicles is in the near future.”

The research team now plans on studying the impact of autonomous vehicles in denser traffic with more freedom given to the human drivers.