The highway stretches across Marin and Solano Counties through the colorful mosaic of marshland in the San Pablo Bay north of San Francisco. But state Route 37’s scenic roadway is vulnerable to sea level rise, which could submerge the highway as soon as 2040, and is subject to brutal bottlenecks during peak hours as commuters circulate between counties. The doomed Bay Area highway that sees over 40,000 drivers a day has a fix in the works — but not everyone agrees it’s the right one. As shovels and bulldozers from Caltrans prepare to widen Highway 37 in a $500 million project, tides continuously chip away at the road’s edge. Its western half near Novato is subject to repeated flooding, especially during king tides, while the eastern span is protected by a series of levees and dikes. ​​