Officials Celebrate Progress Of Marin-Sonoma Narrows Project

Marin County/Sonoma County, CA — Officials with Caltrans, the Sonoma County Transportation Authority and the Transportation Authority of Marin held a dual event Wednesday to celebrate the completion of parts of the Marin-Sonoma Narrows project and the start of another phase.

Officials held a groundbreaking ceremony for the start of construction for the realignment and widening of U.S. 101 at San Antonio Creek at the Marin-Sonoma county line. A ribbon-cutting ceremony for the completion of the Petaluma River Bridge and the State Route 116/Lakeville Highway Interchange was also held.

The new phase represents another step toward having 17 miles of continuous carpool lanes through Sonoma and Marin Counties. Carpool lanes will be added, the San Antonio Creek Bridge will be replaced and a section of the highway will be moved out of the floodplain, according to a news release.

The entire project will expand the U.S. 101 corridor to six lanes throughout the Narrows, adding High Occupancy Vehicle facilities and updating infrastructure connecting the freeway to local roads.

Transportation partners for the MSN 101 project include Caltrans, the Federal Highway Administration, California Transportation Commission, Sonoma County Transportation Agency, Transportation Authority of Marin, Metropolitan Transportation Commission, counties of Marin and Sonoma and the cities of Novato and Petaluma.

The projects represent a significant investment by Caltrans, the California Transportation Commission and local agencies, officials said in the news release.

“We are pleased with the work that has been accomplished so far,” said Caltrans District 4 Director Bijan Sartipi. “It lays the foundation for the proposed HOV lanes currently being discussed.”

Proposition 1B, through which the state has allocated $19.1 billion for transportation projects, has provided $181 million in funding for all MSN projects.

"When the people of California voted for the Proposition 1B transportation bond, they wanted to see results,” said Caltrans Director Malcolm Dougherty. "I am pleased that we are moving forward to update our state’s infrastructure and are improving mobility on this important transportation corridor in the North Bay.”

However, $276 million in additional funding is needed to finish the carpool lane in Marin County, complete a second phase at the new Petaluma Boulevard South Interchange and construct new HOV lanes between State Route 116 and Old Redwood Highway in Petaluma, officials said Wednesday.

“While I am thrilled that we have completed these foundation laying infrastructure improvements, we still have a funding need to complete the much needed HOV lanes,” said Supervisor David Rabbitt. “All the partners should be commended for delivering these improvements, including a new bridge that will last far into the future and eventually carry that third lane we so desperately need.”

Dianne Steinhauser, executive director of the Transportation Authority of Marin, said agencies have had to be creative and work together to secure funding to make these projects happen.

“The current $65 million project, funded primarily by the state, is an important step forward, but unfortunately there are still funding shortfalls to complete the entire 17-mile project," Steinhauser said.

More information about the MSN 101 project can be found online at SCTA’s website, TAM’s website or the Caltrans District 4 website.