Mark Thomas Selected for $191M I-680/SR 4 Interchange Improvements
Mark Thomas has been selected to provide preconstruction and construction management services for the $191M I-680/SR 4 Interchange Improvements, enhancing safety, traffic flow, and connectivity in Contra Costa County.
Mark Thomas has been selected to provide preconstruction and construction management services for the $191 million I-680/SR 4 Interchange Improvements, Phases 2A and 4 project in Contra Costa County.
In partnership with Contra Costa Transportation Authority, we will be overseeing the construction of Phases 2A and 4 to improve traffic flow, enhance safety, and reduce congestion at this critical junction. Phase 2A will widen the diagonal ramp from eastbound SR 4 to southbound I-680, expand the loop ramp, and add auxiliary lanes. Phase 4 will construct a two-lane direct connector from southbound I-680 to eastbound SR 4, realign ramps, and install new ramp metering facilities.
We’re ready to begin preconstruction activities, deliver detailed constructability and biddability reviews, and oversee the successful delivery of this large-scale project. These improvements will make travel safer and more efficient for thousands of daily commuters, supporting economic growth and improving quality of life in the region.