I-80 Gilman Interchange Improvement Project

Interchange Transformation at Interstate 80 and Gilman Street Now Complete

Motorists, bicyclists, and pedestrians will experience safer and more efficient travel in one of the city’s most congested corridors, now that a $100 million project to transform the Gilman Street interchange on Interstate 80 is finished.

After a two-phase buildout, the project includes modern roundabouts on both sides of the interstate, a bicycle and pedestrian overcrossing above the freeway, a new street-level bicycle/pedestrian pathway through the interchange and a new connection to the Bay Trail, which closed the gap between Berkeley and Albany.

"The I-80-Gilman Interchange improvement project is exactly the kind of effort Alameda County voters envisioned when they approved Measure BB to fund local transportation projects," Remarked Board of Supervisors President and Chair of the Alameda County Transportation Commission, David Haubert. “Our efforts are already delivering a safer, more streamlined interchange that supports all travelers. With the improvements we are celebrating today, this interchange will make mobility safer, reduce congestion, and improve access to the waterfront and the Bay Trail.”

“This comprehensive project is a prime example of how reimagined transportation infrastructure can better serve all Californians, regardless of their travel mode of choice,” said Caltrans District 4 Director Dina El-Tawansy. “Innovative design, strong collaboration and community input worked in concert to deliver a passage that is safer, more efficient and better connected to the neighborhoods it serves.”

Representatives from Caltrans, Alameda County, the City of Berkeley and local transportation agencies formally announced the interchange opening, today during an 11 a.m. ceremony on Gilman Street in Berkeley.

The $100 million project was funded through a combination of local, state and federal sources. Senate Bill (SB) 1, the Road Repair and Accountability Act of 2017, contributed $4.1 million and federal programs added $3.1 million. Meanwhile, $53.8 million in funding came from the State Transportation Improvement Program (STIP), $34.3 million from local voter-approved Measure BB and nearly $5 million from local and regional partners such as the City of Berkeley, East Bay MUD and the Bay Area Air District. Caltrans led the development effort, with input from the Alameda County Transportation Commission in partnership with the cities of Berkeley and Albany.

The I-80/Gilman interchange provides critical access to local businesses, parks and other destinations, and is a vital link for regional bike and pedestrian networks. The improvements reflect broad input from residents, businesses and advocacy groups, and demonstrates the region’s commitment to multimodal travel and sustainability. The upgrades address long-standing concerns at the interchange, previously known for complicated intersections and limited access for people who walk and bike, by delivering infrastructure that prioritizes safety and accessibility for all users.

SB 1 provides $5 billion in transportation funding annually split between the state and local agencies. Road projects progress through construction phases more quickly based on the availability of SB 1 funds, including projects that are partially funded by SB 1.

Visit build.ca.gov to learn more about transformative infrastructure projects happening in communities throughout the state. For more information about I-80/Gilman Interchange Project, visit: https://www.alamedactc.org/programs-projects/highway-improvement/i80gilman

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Overview

Caltrans and the Alameda County Transportation Commission (Alameda CTC) in cooperation with the cities of Berkeley and Albany began construction in May 2021 on the Gilman Interchange Improvement Project at the Interstate 80 Gilman Street exit in Berkeley.

The project will enhance safety and improve traffic operations along Gilman Street between West Frontage Road and 5th Street through the I-80 Interchange.  The main project components are two roundabouts at Gilman Street intersections on both sides of I-80, as well as a new bicycle/pedestrian overcrossing over I-80 and bicycle facilities at and near the interchange.  The project will also close the gap in the Bay Trail at the west end of Gilman Street and create a dedicated two-way cycle track along Gilman Street from the interchange to Fourth Street.

Project Purpose

• Simplify and improve navigation, mobility, and traffic operations on Gilman Street between the West Frontage Road and 5th Street through the I-80 interchange
• Reduce congestion, vehicle queues, and traffic, bicycle, and pedestrian conflicts
• Improve local and regional bicycle and pedestrian facilities through the I-80/Gilman Street interchange
• Enhance safety for drivers, pedestrians, and bicyclists at I-80/Gilman Street interchange

The Gilman Street Interchange Project is being constructed in two separate construction contracts:

1. Gilman Street Pedestrian Overcrossing Project – Phase 1

Project Scope

Construct a bicycle/pedestrian overcrossing south of Gilman Street similar to the crossing over I-80 at University Avenue, began in May 2021. It will involve ramp closures on I-80, street closures and brief overnight closures of I-80 in one direction at a time. Work on this phase was concluded in 2023.

2. Gilman Street Roundabouts Project – Phase 2

Project Scope

The second phase, building a double roundabout, is scheduled to begin in July 2022 and complete in 2024, weather permitting. Periodic closures of Gilman Street, local streets and freeway ramps will be necessary to construct the project. Work on this phase is expected to conclude in 2024.

Available Documents

Environmental Document:
Initial Study with Negative Declaration / Environmental Assessment with Finding of No Significant Impact

Traffic Advisories

• Roundabouts, Bike Lanes and a Nature Path Highlight $100 Million Caltrans Project in Berkeley
• Temporary Nighttime Closures for Paving for the I-80/Gilman Street Interchange Project Final Paving Scheduled the Week of November 19, 2024
• Temporary Closures of Gilman Street at I-80 Gilman Interchange in Berkeley September 3rd and September 4th, 2024
• Traffic Switch at I-80 Gilman Street Interchange in Berkeley August 5, 2024
• Traffic Switch at I-80 Gilman Street Interchange in Berkeley July 10, 2024
• Update: Gilman Street to Close Between Second and Fourth Streets in Berkeley Mid- to Late April through Mid- to Late June 2023
• 12-Hour Overnight Closure of Gilman Street at the I-80 Gilman Interchange in Berkeley November 11-12, 2022

Links

Alameda County Transportation Commission – Gilman St Interchange Improvement Project Page

Contact

For additional information, contact Public Information Officer Hector Chinchilla at Hector.Chinchilla@dot.ca.gov.