Express Lane Completion
The Interstate 680 (I-680) Express Lane Completion project is part of the Contra Costa Transportation Authority’s (CCTA) INNOVATE 680 program, which seeks to implement a suite of six projects that, when operating together, will address corridor-wide congestion, travel delays, and operational challenges.
The Express Lane Completion project proposes to construct a northbound express lane from Livorna Road to State Route 242 (SR-242). This project would also convert the existing northbound High-Occupancy Vehicle (HOV) lane that runs from SR-242 to the Benicia-Martinez Bridge Toll Plaza to an express lane. The goal of the project is to complete the I-680 express lane network through Contra Costa County to increase travel speeds for those choosing to travel by carpool, vanpool, or motorcycle. CCTA, in partnership with the Metropolitan Transportation Commission (MTC) and the California Department of Transportation (Caltrans), has started preliminary design and environmental analysis on the Express Lane Completion project to better understand possible solutions that will improve operations and mobility on this critical corridor.
This project will address the lack of continuous express lanes within the county, which leads to increased travel time for all users.
A key priority for this project is to smooth traffic throughout the corridor, where delays can reach up to 30 minutes* when traveling from one end of the county to the other.
*Based on INRIX data, Nov 2019
To reduce bottlenecks along the corridor, this project will address weaving issues like those at the Lawrence Way on-ramp and Treat Boulevard off-ramp in Walnut Creek, which regularly cause traffic to back up to the SR-24 interchange.
Estimated construction costs range from $257-$358 million in current dollars. Right-of-way costs will range from $3.5-$5.5 million. These are preliminary estimates that will be adjusted as the project is further defined. This project is eligible for a variety of funding source types, including:
Reduce peak-period congestion and delay
Optimize use of existing HOV lane capacity
Improve travel time reliability
Provide efficient travel options for all vehicles
The project team is currently conducting an Environmental Analysis with the following activities:
- Defining feasible Build Alternatives for study
- Performing traffic studies
- Initiating preparation of environmental studies
- Completing environmental field work
- Initiating engineering studies
- Continuing coordination with agency stakeholders including California Highway Patrol, Bay Area Rapid Transit, and local jurisdictions
A wide variety of resource areas are currently being studied as part of the Environmental Studies including: