highway. White Slough and Sonoma Boulevard interchange To protect White Slough while still allowing the widening of SR 37, the White Slough Protection and Development Act was passed in 1990. It allowed up to 13 acres of wetlands to be filled but required at least four times as much wetland restoration elsewhere in the Bay Area. After environmental studies on the White Slough, Caltrans widened and elevated that section of the road and converted it to a freeway. To accommodate bicycles and pedestrians, a cycleway was built along the eastbound side of the freeway. Finally, Caltrans completed the overpass which crossed SR 29, Broadway, and Mini Drive (bypassing Marine World Parkway, three traffic signaled intersections, and a railroad grade crossing). The project was completed in the summer of 2005, and fully open to traffic on August 20. 2019 flooding The highway is increasingly subject to flooding as the route is near sea level. The road was closed for a total of 28 days during the winter of 2016-17. On the morning of Friday February 15, 2019, the westernmost portion of the westbound highway (between Atherton Ave. and U.S. Route 101) was closed due to flooding caused by a levee break. Marin County declared a state of emergency, and public works crews worked 24 hours a day pumping water and repairing the levee. It was expected to be closed for at least a week, however the highway fully reopened on the morning of Wednesday, February 20, 2019. Future In 2017, it was estimated that it would cost $4 billion to fix all the flooding, traffic, and other issues along the corridor, and based on transportation funding levels it would take until 2088 to come up with that amount of money. In 2022, California State Senator Bill Dodd introduced new legislation that would make the highway a toll road between Sears Point and Mare Island. The proposed law would use the toll revenues to help pay for the flooding and traffic improvements. Major intersections Popular culture Train's 2012 album California 37 is named after State Route 37, with the album cover prominently featuring the route's highway shield. AFI released a song titled "Rabbits Are Roadkill on Rt. 37" on its 2006 album Decemberunderground. See also References External links Caltrans: Route 37 highway conditions Road Ecology Center (UC Davis): State Route 37 planning for sea level rise adaptation California Highways: Route 37 Sonoma