Caltrans will be closing a 9-mile stretch of Highway 4 from Discovery Bay in Contra Costa County to Roberts Road in San Joaquin County over the next two weekends.

The highway will close at 10 p.m. Friday and reopen at 5 a.m. Monday. A second closure is scheduled from 10 p.m. July 17 through 5 a.m. July 20.

Drivers are advised to use Interstate 205 and Byron Highway as alternate routes, which may cause delays of approximately 30 to 40 minutes. Local access within the closure limits will be provided to residents and local businesses, according to Caltrans.

The closures are part of the $21.6 million Highway 4 Delta Pavement Improvement Project. Caltrans began construction in early April, and the project is expected to be completed by February 2027, agency officials said.

A graduate student at UC Berkeley's Graduate School of Journalism, Emily focuses on business and health reporting. She is especially interested in covering economic and community development issues in Contra Costa County.