Schedule: Hours scheduled to be changed by February

Marin County and Sonoma County - Caltrans and its transportation partners, the Metropolitan Transportation Commission (MTC), the Transportation Authority of Marin (TAM) and Sonoma County Transportation and Climate Authorities (SCTCA) have agreed to reduce High-Occupancy Vehicle (HOV) hours in early 2026 for both counties.

Permanent HOV hours will be decided by the end of January 2026 and scheduled to be changed in February 2026. The exact hours will be determined after Caltrans completes its traffic analysis along the US-101 corridor in January.

The new hours will continue to be consistent in Marin and Sonoma and will cover peak commute hours in both directions in both the morning and afternoon/evening.

Signs will be updated along the entire length of the HOV lanes, stretching from Richardson Bay Bridge in Marin County and Windsor in Sonoma County.

The current HOV lane hours in both counties are 5 a.m. to 10 a.m. in the mornings and 3 p.m. to 7 p.m. in the evenings, Monday through Friday.

With the completion of the three-lane configuration in the Marin Sonoma Narrows project in 2025, there are now 52 miles of continuous carpool lanes on US-101. There is one HOV lane in each direction of US-101. The new HOV lanes are the second longest in California.

HOV lanes reduce traffic by carrying more people in fewer vehicles and encouraging carpooling and transit to improve freeway efficiency. For more information about the current HOV lane hours, see bit.ly/3HoVfOO.

Caltrans, in partnership with its transportation partners, activated nine ramp meters along northbound and southbound US-101 in Marin and Sonoma counties on Tuesday, Dec. 2. Caltrans is scheduled to activate the ramp meters at Rowland Boulevard diagonal on-ramp to Southbound US-101 in Novato starting Tuesday, Dec. 23.

More ramp metering is scheduled along the corridor as funding becomes available.

Please drive with caution. Slow for the Cone Zone and Be Work Zone Alert.

For 24/7 traffic updates, please visit 511.org: https://x.com/511SFBay
For real-time information, visit Caltrans QuickMap: https://quickmap.dot.ca.gov
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Or call 1-800-472-7623, 1-800-427-ROAD for state highway conditions statewide.