Martinez, CA: The Contra Costa Transportation Authority (CCTA) and the California Department of Transportation (Caltrans) are constructing the first phase of a multi-phased project to improve safety and help reduce congestion at the Interstate-680/State Route 4 Interchange in central Contra Costa County. In order to facilitate a key phase of construction that will shift traffic onto newly constructed facilities, the agencies are planning significant traffic shifts prior to, during and after the Memorial Day Weekend which will impact SR-4 and both of the I-680 connector ramps spanning Martinez, Pacheco, and Concord. CCTA and Caltrans have scheduled the closures during evening/nighttime hours and over the weekend in order to minimize impacts to the motoring public.
Nightly lane closures of SR-4 (from Pacheco Boulevard to Solano Way) and the I-680 connector ramps in both directions (northbound and southbound connectors to SR-4) will continue from May 28 –31, 2020. The work taking place during this time will enable traffic to move onto newly constructed facilities as they are completed, including:
- Northbound Interstate 680 connector ramp to Eastbound State Route 4
- Westbound State Route 4 connector ramp to Northbound Interstate 680
- New Grayson Creek Eastbound and Westbound bridges
- Shifting traffic onto the new median concrete pavement widening on State Route 4 between Pacheco Boulevard and Walnut Creek Bridge
Planned closures include:
Thursday, May 28 through Sunday May 31, 2020: Varies by evening, see below for specific times
Nightly full freeway closures for Eastbound and Westbound State Route 4 and full closure of the
- Full ramp closure of Eastbound SR-4 connector to Northbound I-680
- Full ramp closure of Southbound I-680 connector to Eastbound SR-4
- Full Ramp closure of Northbound I-680 connector to Eastbound SR-4
Thursday, May 28, 2020: 11:00 p.m. and 5:00 a.m.
Full freeway closure of Eastbound SR-4 from Pacheco Boulevard to Solano Way including full ramp closures listed above.
Friday, May 29, 2020: 10:00 p.m. and 8:00 a.m.
Full Freeway closure of Westbound SR-4 between Solano Way and Pacheco Boulevard including full ramp closures listed above.
Saturday May 30, 2020: 12:00 a.m. and 8:00 a.m.
Full Freeway closure of Eastbound SR-4 between Pacheco Boulevard to Solano Way including full ramp closures listed above.
Sunday May 31: 8:00 p.m. and 6:00 a.m.
Full freeway closure of Westbound SR-4 between Solano Way and Pacheco Boulevard including full ramp closures listed above.
Motorists are advised to be alert for on-site closure and detour signs, and to Slow for the Cone Zone. Please drive with caution through the detours and leave a safe traveling distance between your vehicle and vehicle ahead of you. Please note that the construction schedule and closure
information presented here are subject to change based on weather and other conditions. We
appreciate everyone’s patience and cooperation as we work to complete these important
About the Interstate 680/State Route 4 Interchange Improvement Project
The Interstate 680/State Route 4 Interchange Improvement Project will widen approximately four miles of State Route 4 in both directions between Morello Avenue in Martinez and State Route 242 by adding a third lane in the eastbound and westbound directions to improve on-ramp and off-ramp merging. The project also includes widening of five structures, extending eastbound State Route 4’s carpool lane approximately two miles, installation of safety lighting, and replacement of the Grayson Creek Bridge to bring it up to current State bridge safety codes. This segment of work in this multi-phased project will lay the groundwork for future improvements to connector ramps, improve traffic safety and enhance traffic flow.