Drivers in the Bay Area have long dealt with congestion, bottlenecks and increased travel times on some of the busiest highways in the U.S. I-680 connects the southern San Francisco Bay Area with I-80 and the major north-south freeway is a heavily traveled and key corridor for the region. To maximize highway operations, the Contra Costa Transportation Authority, in cooperation with the Metropolitan Transportation Commission, Caltrans and the Federal Highway Administration, constructed 11 directional miles of express lane on southbound I-680 from the Benicia-Martinez Bridge to the City of Walnut Creek. The project connects to existing southbound express lane that runs from Walnut Creek to San Ramon creating a 25-mile continuous express lane system along the entire
I-680 corridor in Contra Costa County.

HDR will receive a 2022 Merit Award by ACEC for South Bound I-680 HOV Lane Completion & Express Lane Conversion Project. PARIKH will also be recognized for geotechnical services provided on this project. PARIKH worked with HDR on all phases of the project, providing preliminary engineering, environmental assessment and documentation, through design phases.

The project included conversion of the existing southbound HOV lane into a tolled express lane, and construction of a new express lane to close an existing 3-mile gap in the managed lane system. Project features included freeway widening, interchange modifi cations, retaining walls, bridge widening, overhead sign structures, communications and electrical infrastructure for the toll system.

The project traverses an urbanized, residential, commercial and industrial areas with many physical constraints including limited right-of-way, complex interchanges and structures, and various wetlands and marsh habitat. The project was further complicated due to the need for two separate construction contracts, Civil and TSI, that would need to be tightly coordinated, and an existing express lane that would need to remain in operation throughout construction.
The project goals were to optimize the use of the existing HOV lane capacity, to provide a reliable travel time option by managing traffic through congestion-based pricing, and to create a seamless network of express lanes to encourage carpools and transit. To provide the traveling public with early benefits, the $127 million project opened to traffic as a High-Occupancy Vehicle Lane one year ahead of schedule in August 2020. The toll system integration and testing continued while the HOV lane was open to traffic; the lane officially opened for tolling in August 2021.

(Source: HDR)