Drivers on Reliez Valley Road and other affected routes in the Lafayette area should expect delays of up to 10 minutes starting Monday, Aug. 24, as Contra Costa County begins a $1.59 million guardrail replacement project across nine unincorporated areas.

The work runs through Nov. 17, weather permitting. Crews will replace aging guardrails with the Caltrans-standard Midwest Guardrail System at multiple locations countywide, installing concrete anchor blocks and small retaining walls, according to the county’s project page.

Construction hours are 8 a.m. to 4 p.m. weekdays, excluding holidays. The county’s public alert said traffic control will be monitored to minimize impacts during commute hours, and message boards and construction signage will alert drivers to active work zones.

Beyond Lafayette, the Phase II project covers roads in Walnut Creek, Alamo, Danville, Pleasant Hill, Rodeo, El Sobrante, East Richmond Heights and San Pablo. San Pablo Dam Road, Olympic Boulevard, Pleasant Hill Road, Taylor Boulevard and Danville Boulevard are among the roads receiving upgrades countywide.

The county has not published a full list of affected Lafayette intersections. Reliez Valley Road is the only Lafayette-area road specifically named in the project documents.

Contra Costa County Public Works is overseeing the project, which is funded by a state Highway Safety Improvement Program grant and Gas Tax revenue. The contract was advertised May 5 with bids due June 9.

Residents with questions can contact county spokesperson Kelly Kalfsbeek at 925-313-2115.