State Sen. Bill Dodd, D-Napa, has introduced two bills designed to ease congestion on state Highway 37 — which runs between Vallejo and Novato and traverses Solano, Sonoma, and Marin counties — and to protect it from sea level rise.

Dodd proposes adding a toll to pay for “critical improvements” and would like to tap into nearly $2 billion in federal infrastructure funding as well, his office announced last week.

“Congestion and seasonal flooding are already unbearable for commuters and it will only get worse with the highway projected to be underwater in 20 years,” he said in a statement.

Highway 37 is notorious for congestion during peak times. It is already prone to seasonal flooding; that, coupled with areas of the expanse that are one-lane both ways, have made the artery problematic.

Caltrans has warned of sea level rise affecting the stretch of highway.

“Nearly the entire length between Novato and Vallejo is predicted to become permanently submerged as sea levels rise if modifications are not made,” the agency said.

Dodd said that one plan is to create a raised causeway, which he estimates would cost “billions of dollars.”

Senate Bill 1050 would authorize the creation of a toll between Mare Island Way in Vallejo and Sears Point, which is midway in the span at state Highway 121 in Sonoma County. Dodd’s office says the revenue would finance construction and environmental remediation and “could be used to leverage state and federal funding.”

The second bill, Senate Bill 1049, would direct $1.9 billion in federal infrastructure funds to “climate-adaptive transit projects.”

Dodd’s spokesperson said that the state senator had previously put forth this legislation in 2020 but withdrew it due to the pandemic.