‘Narrows’ project on Highway 101 nears new milestone

Work on the notorious 16-mile stretch of Highway 101 between Petaluma and Novato known as “The Narrows" is about to hit a new milestone, Caltrans announced – but first a ”traffic shift“ must take place as crews link up old and new parts of the highway.

Crews will be performing “paving and K-rail adjustment work leading to a traffic shift ... in both directions from Novato near Olive Avenue to San Antonio Road,” the agency said in a news release. Although announced for Thursday, April 11, the agency noted that “specific times and dates and nighttime ramp closures will be announced in the coming days.”

During the work, “southbound traffic will be realigned away from the temporary median lanes, into the newly constructed Southbound U.S. 101 road section. That section has been raised to match the median that was opened back in June 2023.” In addition, “northbound U.S. 101 traffic will be realigned into those same temporary median lanes now moving in the opposite direction, as the next phase of construction begins to reconstruct the old northbound road section.”

Caltrans describes the new lanes as part of the "final phase of a decade-long widening project in Marin and Sonoma counties meant to relieve traffic congestion on the corridor.“

A year ago, “Caltrans diverted southbound U.S. 101 traffic onto new elevated lanes spanning San Antonio Creek to just north of Atherton Avenue in Novato. This was the first major milestone for the project.”

Drivers are asked to watch for signs and messages along the 16-mile stretch as timing for the roadwork nears. California Highway Patrol officers will be present during the work.

Real-time traffic updates are available at twitter.com/511SFBay and at quickmap.dot.ca.gov.