Countra Costa County, CA

I-680 and SR-4 Interchange Widening

This project proposes to widen 4 miles of State Route 4 (SR-4) in both directions to provide an additional lane in each direction including a managed lane facility in the eastbound direction. The proposed improvements include freeway to freeway ramp modifications; new auxiliary lanes; widening of 5 bridge crossings; and replacement of 1 bridge crossing; retaining walls; utility relocations; drainage facilities; overhead sign structures; and, safety lighting and TOS upgrades.

Extensive environmental permitting and mitigation requirements are needed for two creek crossings from US Army Corps of Engineers, Department Fish and Wildlife, and Regional Water Quality Control Board. Right-of-way requirements are needed from 3 parcels and one parcel requires an eminent domain process. This is a priority project for CCTA to expedite congestion relief on this critical segment of SR-4.





Contra Costa Transportation Authority


Contra Costa Transportation Authority