Overnight Full Closures of State Route 4 (Marsh Creek Road) Between Vasco Road and Byron Highway in Contra Costa County Extended

Extended to Wednesday, June 3, 2026; nightly closures from 7:30 PM to 5:00 AM (Sunday through Thursday).

Contra Costa County - Caltrans has extended paving work on State Route 4 (SR-4) between Hillcrest Avenue and Byron Highway. Full closures of SR-4 Marsh Creek Road from Vasco Road to Byron Highway will continue nightly, Sundays through Thursdays, from 7:30 PM to 5:00 AM, until June 3, 2026. Only local residents, business owners, and employees can access the closed section during these hours.

Please note all work is weather dependent and subject to change.

State Route 4 Marsh Creek Road Detour Information:

• Westbound SR-4 Travelers: Detour begins at Byron Highway left on Brentwood Boulevard, left on Balfour Road, right on to westbound SR-4.

• Eastbound SR-4 Travelers: Detour begins at Vasco Road; left on Walnut Boulevard, right on Payne Ave, left on Sellers Ave, right on Brentwood Boulevard, continue on Byron Hwy to eastbound SR-4.

Changeable message signs (CMS) will be posted throughout the corridor to assist drivers. Please follow posted signs and detour routes during these closure periods.

Motorists are advised to expect delays and allow extra travel time.

To search for current District 4 lane closure information, please click here.

^{Crews conducting paving work on SR-4 Marsh Creek Road in Contra Costa County}

For 24/7 traffic updates, please visit 511.org: https://x.com/511SFBay
For real-time information, visit Caltrans QuickMap: https://quickmap.dot.ca.gov
Follow us on X: https://x.com/CaltransD4
Or call 1-800-472-7623, 1-800-427-ROAD for state highway conditions statewide.