In the News: Alexandre Bayen and team show how traffic-beating apps can make congestion worse

Featured Faculty: Alexandre M. Bayen

Professor Alexandre Bayen and a team of researchers show how the ever-growing number of people who use traffic-routing apps may alleviate traffic woes for individuals but create a deterioration of driving conditions overall.

The group presented their work earlier this year at the Transportation Research Board’s annual meeting and at the Cal Future conference at Berkeley in May 2017. They’ve also published work examining the negative externalities of high levels of automatic routing.

In the Cal Future talk, Bayen walked through a simulation created in the commercial-transportation simulator Aimsun. The video below shows how the flow of a freeway changes in response to an accident under two conditions: when no drivers use routing apps and when only 20 percent of drivers use routing apps. When there are more app-using drivers, congestion builds up at off-ramps, creating more traffic on the freeway.

Although these apps can put stress on local side streets, the effect on highways, or for traffic systems as a whole, is still unknown.

"This is an open problem,” said Bayen. “Hence, we need to be very cautious in our conclusions.”

See The Perfect Selfishness of Mapping Apps (The Atlantic, 3.15.18)

Published 03/16/2018