At long last, highway widening moves to Petaluma

After two decades and more than $1 billion, work on the Highway 101 widening project has finally made it to Petaluma.

Officials kicked off the start of the Petaluma construction project last week with a groundbreaking for the 3.3-mile segment from Corona Road to Lakeville Highway. It is the last gap of four-lane highway from the Marin County line to Windsor.

For reasons that are still unclear, Sonoma County transportation officials decided to leave Petaluma for last. After Highway 101 was widened through Santa Rosa, work moved north to Windsor and south through Rohnert Park and Cotati.

Eventually, funds were pieced together to widen the Petaluma River bridge and then the highway south of Petaluma to the county line. And now, bringing up the rear, it’s Petaluma’s turn.

A big reason we were able to widen the freeway at all was the 2004 passage of Measure M, the quarter-cent sales tax that supports transportation projects. The Sonoma County Transportation Authority has been able to leverage Measure M money to attract state and federal highway funds on a 5 to 1 ratio, meaning for every $1 of local tax money, there is $5 of outside money in the highway project.

Having a local transportation tax is key to making us a so-called “self-help” county - when we go to the state and feds for money, they know we have skin in the game. It’s an important distinction, and one worth remembering next year when the SCTA looks to extend Measure M on the November 2020 ballot.

At that point, the Highway 101 project will be fully funded, and sales tax money can be allocated to other priorities. Local streets, transit, SMART, bike paths could all see significant improvement if Measure M is extended. Perhaps the SCTA can repeat its leveraging success with Measure M on Highway 37, the next big North Bay infrastructure project.

Also worth noting, the $121 million project through Petaluma is mostly funded by the new state gas tax increase. If the legislature hadn’t increased the gas tax and voters hadn’t turned back a referendum challenge in 2018, then we would not have had $85 million for the project, and the Petaluma Gap would refer to the freeway not just a wine growing region.

Drivers will notice construction over the next three years, but at the end of 2022, we will have six freeway lanes through the heart of Petaluma. There are a couple of other nice additions to this project.

Petaluma residents who live alongside the freeway will finally get some privacy in the form of sound walls. Several homes were left naked to the traffic after a 2016 fire destroyed a grove of eucalyptus trees that provided a buffer. Officials stipulated that the sound wall project will be the first order of work.

The East Washington Street interchange will get some improvements that should help with traffic flow on Petaluma city streets. Specifically, the northbound off ramp will terminate farther west, which will provide more room for cars turning right and ease traffic at the busy McDowell Boulevard intersection.

Officials fittingly broke ground at the spot where Rainier Avenue currently terminates at Highway 101. When the project is complete, there will be a gaping hole under the freeway at this location. Petaluma paid $7 million for a new underpass to allow for an extension of Rainier across town to Petaluma Boulevard North.

Raising the freeway at this spot has been the single biggest hurdle to completing the Rainier crosstown connector. It will be easier to imagine a path forward for Rainier once there is literally a path forward.