Express Lane Completion


icon blue part time transit lanes 2The 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.
Express lane highway traffic graphic



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:


fact sheet peak period congestion icon 1

Reduce peak-period congestion and delay

fact sheet icon hov lanes

Optimize use of existing HOV lane capacity

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Improve travel time reliability

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Provide efficient travel options for all vehicles


NB Transit Lane timeline graphic

For more info about this project, contact:

Stephanie Hu – Director, Projects
Contra Costa Transportation Authority

Environmental Phase

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:

Air Quality

Biological Resources

(habitats, threatened & endangered species, wetlands)

Climate Change / Greenhouse Gases

Community Impacts

Cultural Resources

(archaeology, historic buildings & structures, tribal cultural resources)

Cumulative Impacts

Economic Impacts

Environmental Justice


Geology, Soils & Seismicity


Hazardous Materials & Waste

Land Use



Right-of-Way & Relocation

Sea Level Rise

Traffic (VMT)


Visual Resources

Water Quality, Hydrology & Stormwater

Public Scoping Meeting Archive

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We welcome and encourage your participation in this important project. If you are interested in the Project presenting to your organization or association, please contact us at or leave a message at (925) 278-5978.