Here You Come Again: Third Change To Sonoma Marin Carpool Hours On HWY-101

PETALUMA, CA — Just when drivers were getting themselves together for the commute, Highway 101 carpool hours have changed again.

For the second time in six months, commuters on Highway 101 in Sonoma and Marin counties are adjusting to new carpool hours on the 52-mile corridor —in both directions and in both counties stretching from the Richardson Bay Bridge to Windsor.

As of Monday, signs announcing the latest carpool lane hours now read 6 to 9 a.m. and 3 to 6:30 p.m.

Some commuters have themselves to blame for the change, which follows months of complaints by such drivers about the longer hours. The complaints, petitions, and pressure from local and state officials helped to reverse the changes made in July, shaving off two hours in the morning of frustration and increased gridlock when Caltrans activated the new hours in September 2025.

Officials conceded that the longer hours for carpool-only lanes led to congestion and delays, but they put some of the responsibility for the problem on new rules for electric cars.

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