Drivers heading from San Francisco to the East Bay at night should brace for some slow going the next two months. Caltrans has kicked off lane closures on the eastbound direction of the western span of the Bay Bridge five nights a week to make way for maintenance. Quintana said Caltrans delayed full lane closures on Sunday night to accommodate fans heading home from the Outside Lands music festival. While the closures officially began Sunday night, Caltrans has been performing work for months that’s led to extended lane closures and delays. For residents on Treasure Island who rely on the Bay Bridge, it’s already proved a hassle.