August 19, 2022

This traffic-choked section of Highway 101 has been under construction for two decades. Here’s when it will wrap up

The end is finally in sight for one of the Bay Area’s longest-running highway projects:…

The end is finally in sight for one of the Bay Area’s longest-running highway projects: the Marin-Sonoma Narrows widening on Highway 101, where construction has been going on for over a decade.

By July 2026, the final stretch of the project to unlock one of the Bay Area’s nastiest traffic choke points should be completed, Caltrans and North Bay transportation officials said.

Construction started this month on the final stretch of the complicated project to widen the highway near the point where it straddles the Marin-Sonoma county line by adding a part-time carpool lane.

Transportation officials and dignitaries held a ribbon-cutting ceremony this week to mark the beginning of the end.

The last piece of the project will widen the roadway and bridges on a stretch just south of the county line — about 5 miles in the southbound direction and 3.5 miles in the northbound direction. Work will include modifying the Redwood Landfill interchange.

If it seems like construction on Highway 101 between Novato and Petaluma has been going on forever, there’s a good reason.