New Highway 101 ramp meters in Sonoma and Marin counties will be activated starting Tuesday to help manage traffic flow, according to Caltrans. Caltrans will turn on seven meters, which are traffic signals at onramps, in Sonoma County and five in Marin County in both northbound and southbound directions, the agency said in a Wednesday news release. All of the Sonoma County meters and both Marin County northbound meters will be switched on Tuesday. Three southbound Marin County meters, which are located along the Marin-Sonoma Narrows project area, will be turned on after some additional drainage and electrical work is completed, likely in early 2026, Caltrans spokesperson Matt O’Donnell said in an email Wednesday. The meters located in Petaluma, Novato, Sausalito and Mill Valley will be active at varying hours Monday through Friday. Signs will be placed ahead of the meters, letting drivers know of the new traffic signals. In Sonoma County, the meters will be on from 6 to 10 a. m. and 3 to 7 p. m. In Marin County, those leading onto the northbound lanes will be active from 2 to 7 p. m. and the meters by the southbound lanes will be on 5 to 11 a. m. The goal of the new meters is to make the highway more efficient and safe by creating room between vehicles and reducing traffic congestion and delays, the release said. Meters will be placed along additional onramps as funding becomes available. These are the locations where meters will be activated in Sonoma County: North Old Redwood Highway and Petaluma Boulevard loop onramp to northbound North Old Redwood Highway diagonal onramp to northbound Kastania Road and South Petaluma Boulevard diagonal onramp to southbound Lakeville Street and Caulfield Lane hook onramp to southbound East Washington Street diagonal onramp to southbound North Petaluma Boulevard and North Old Redwood Highway hook onramp to southbound Old Redwood Highway and North Petaluma Boulevard loop onramp to southbound In Marin County, meters will be activated at: Shoreline Highway and Almonte Boulevard hook onramp to northbound Redwood Highway Frontage Road and De Silva Drive hook onramp to northbound De Long Avenue diagonal onramp to southbound Atherton Avenue diagonal onramp to southbound San Antonio Road and Redwood Sanitary Landfill Road diagonal onramp to southbound All southbound Marin County meters are located along the Marin-Sonoma Narrows project area. While the expanded Highway 101 lanes opened in September, some “minimal” construction forcing some night closures is planned for later in the fall and winter, delaying the opening of the meters in those spots, O’Donnell said. In spring 2026, Caltrans will resume the final overlay paving and striping of the lanes, which is expected to take two months. The meter project was completed in partnership with the Metropolitan Transportation Commission, the Transportation Authority of Marin and Sonoma County Transportation and Climate Authorities.
https://www.pressdemocrat.com/2025/11/26/new-ramp-meters-along-highway-101-in-sonoma-and-marin-counties-to-be-activated-tuesday/
