Kicking hybrid cars out of the carpool lane has made traffic slower for everyone, according to researchers at UC Berkeley.
Using six months of data from roadway sensors in the Bay Area, the researchers found that after hybrids lost carpool lane privileges, the average speed of hybrids, drivers in regular lanes and drivers in the carpool lane were all slower.
While it is certainly counterintuitive that the average speed in the carpool lane would go down with less cars, UC Berkeley researcher Kitae Jang explained, “As vehicles move out of the carpool lane and into a regular lane, they have to slow down to match the speed of the congested lane. Likewise, as cars from a slow-moving regular lane try to slip into a carpool lane, they can take time to pick up speed, which also slows down the carpool lane vehicles.”
Even though, come January, 40,000 super-clean plug-in-hybrids and hydrogen-powered internal combustion cars will be allowed into the carpool lane, Jang and his colleagues argue that, on top of that, re-administering carpool privileges to the 85,000-some hybrids that lost access will improve traffic speeds further.
Have you noticed slower or faster speeds—and improved or worsened safety—in all lanes since the coveted hybrid yellow sticker stopped granting carpool access? Do you think hybrids should be readmitted to the coveted carpool lanes of Los Angeles?
Michael Cassidy, professor in civil and environmental engineering, UC Berkeley
Brian Taylor director, UCLA Lewis Center; director, Institute of Transportation Studies, UCLA Luskin School of Public Affairs