Highway 37 in the North Bay will be closed from early Saturday until midday Sunday, so repairs can be made to railroad crossings along the vital corridor.
Starting at 3 a.m. on May 20, drivers will be unable to access Highway 37 between Vallejo and Sears Point, creating a lengthy detour onto Highways 29, 12 and 121.
The work to upgrade worn-out railroad tracks and other equipment in the SMART system is scheduled to be completed at 11 a.m. on May 21.
For eastbound drivers, the closure begins in Marin County where Highway 37 meets Highway 121. Westbound drivers in Vallejo will be forced off Highway 37 at Walnut Avenue.
More information about the weekend closure is available from Caltrans.
State transportation officials recently voted to create a toll on this section of Highway 37 that would help pay for widening the congested route.