A new study finds that “connected” vehicles, which share data with each other wirelessly, significantly improve travel time through intersections – but automated vehicles can actually slow down travel time through intersections if they are not connected to each other. The culprit? Safety.

“There are two significant reasons that people are interested in automated vehicles – improving passenger safety and reducing travel time,” says Ali Hajbabaie, first author of a paper on the work and an associate professor of civil, construction and environmental engineering at North Carolina State University.

“There is a lot of research showing that automated vehicles can improve safety. But our research here – which relies on computational modeling – suggests that if we want to also improve travel time, an increase in automated vehicles isn’t enough; we need vehicles that are capable of communicating with each other and with the traffic-control systems that manage traffic flow at intersections.”