Full Highway Closure Of State Route 4 From Tracy Boulevard To San Joaquin/Contra Costa County Line

Closure On Sunday, May 31 From 7:00 A.M. Until 7:00 P.M. - Detour Required

San Joaquin County - Caltrans will perform a full highway closure of State Route 4 (SR-4) from Tracy Boulevard to the San Joaquin/Contra Costa County line as construction progresses to Stage 2 of the Old River Bridge Maintenance Project.

This closure will occur on Sunday, May 31, 2026, from 7:00 a.m. until 7:00 p.m., and is required for the installation of k-rail, channelizers and modified traffic control/lane striping at the Old River Bridge. During this closure the following detour will be required.

• Westbound SR-4 travelers: Closure will begin on SR-4 at Tracy Boulevard. From SR-4, travel south on Tracy Boulevard to I-205 west, exit Mountain House Parkway, travel north to Byron Highway to SR-4.
• Eastbound SR-4 travelers: Closure will begin at Discovery Bay Boulevard. From SR-4, take Byron Highway south to Mountain House Parkway, south to I-205 East, exit Tracy Blvd, north on Tracy Blvd to SR-4.
• Local access: Only residents, emergency vehicles and business owners/employees will have access to locations on SR-4 within the closure limits.

Caltrans will utilize overhead and portable changeable message signs, alerting motorists of the detour and potential delays which are expected to be approximately 30 minutes.

This project is required to install a new polyester concrete overlay to the bridge deck (roadway) surface, install new guardrail systems located at the approaches of each end of the bridge, and painting of the bridge steel structure with weather-resistant paint and materials to increase the reliability and serviceability of this 100-year-old swing span bridge.

Additional in-water work will see the existing timber waling and the fenders on the north side of Pier 3 replaced, while the south side of Pier 2 would be supported with new high-density polyethylene walers mounted to the existing timber piles.

This $9.8 million project is being performed by Disney Construction, Inc. (Burlingame, CA) and is scheduled for 220 working days beginning the week of January 25-31, with completion expected on November 10, 2026.

Schedules are subject to change due to traffic incidents, weather, availability of equipment and/or materials and construction related issues.