And it doesn’t have to cost drivers much or hit low-income drivers hard. That’s because drivers would get a fixed monthly toll “credit” and pay out of pocket only when they exceed the monthly allotment. She calls it “credit-based congestion pricing.” The idea is that those who must use the highways frequently at peak times will pay the most, while others will pay little or nothing. The model results suggest that most of the region’s population would benefit, because the value of their saved time would exceed the toll costs, she says.

The work is early-stage research. To be sure, wide adoption would require drivers to accept having their travel habits electronically tracked. But similar concerns accompanied the installation of RFID tags at today’s tollbooths. Millions of drivers soon forgot about privacy worries when they began speeding past the coin-tossers at tollbooths. And privacy concerns could be addressed if third-party companies handled account information.

If Kockelman’s model is right, the expanded adoption of such technology could provide substantial traffic relief for millions of drivers around U.S. metropolitan areas. “I think most residents of congested regions will feel it’s worth a shot,” Kockelman says. “Congestion is the number-one concern cited by residents of most urban regions in the U.S.”