How are the Bay Area’s carpool lanes working out? How much faster are they?

though carpool lanes generally move faster than regular traffic lanes, more than half of those in the Bay Area — 58 percent — are failing to meet the Federal Highway Administration’s standard: traffic should zip along at 45 miles per hour 90 percent of the time.

Nonetheless, the Bay Area’s carpool lane network is “the most effective in the state,” said Randy Rentschler, legislative director of the Bay Area Metropolitan transportation Commission, which regulates carpool lanes throughout the region.

“We don’t have a bunch of empty lanes, and we have a lot of mass transit in the lanes. We’re the only place in the country besides Washington, D.C., that has a casual-carpool culture,” he said, referring to the informal practice of giving rides to strangers picked up at designated spots to qualify for carpool lanes and discount bridge tolls. “So our carpool lanes move the most people.”

to get a snapshot, we asked the traffic analytics firm INRIX to compare speeds between a carpool lane and a regular one, along a stretch of Interstate 80 from Gilman Street in Berkeley to the Embarcadero exit in San Francisco. After examining data from 2015 to 2017, the analyst found that the carpool lane performed 10 percent better.

AVERAGE TRAFFIC SPEEDS

Traffic was observed on I-80 beTween Gilman STreeT in Berkeley and FourTh STreeT/FifTh STreeT in San Francisco.

WesTbound

(Toward S.F.) MidnighT To 7 a.m.

7 To 10 a.m.

10 a.m. To 3 p.m.

3 To 6 p.m.

6 p.m. To midnighT

EasTbound

(away from S.F.)

MidnighT To 7 a.m.

7 To 10 a.m.

10 a.m. To 3 p.m.

3 To 6 p.m.

6 p.m. To midnighT

24

26

37

37