Hate the Gilman interchange? Safer routes are on the way

Caltrans will begin work in May to install two new roundabouts and a new pedestrian/bike bridge at what some call the “most dysfunctional intersection in the country.”

A rendering of the proposed pedestrian/bike bridge by the Gilman Stree/I-80 interchange.
A rendering of the proposed pedestrian/bike bridge over I-80 at the interchange with Gilman Street. Credit: Caltrans

Seven years after the concept was first presented to the public, Caltrans is set to begin work on installing two roundabouts and a pedestrian/bike bridge by the Gilman Street interchange at I-80.

Work on a bridge to the south of the exit will begin in May and work on the roundabouts will start in November, according to Janis Mara, a spokesperson for Caltrans. The two elements are scheduled to be completed in 2023.

The Gilman interchange at I-80 is one of the most troublesome and confusing in Berkeley with multiple entry points on either side of the freeway. Drivers often report having difficulty merging onto Gilman Street or the frontage roads and don’t know who has the right of way. Cyclists and pedestrians also have to dodge traffic.

Berkeleyside readers have called the area “a ridiculous mess” and “the most dysfunctional intersection … anywhere in the United States.”


The rate of collisions on Gilman by the freeway, and on the freeway on- and off-ramps themselves, is also significantly higher than the state average. Project documents describe the westbound off-ramp from I-80 as the most dangerous area of the interchange, with about two collisions per million vehicles. That’s twice the statewide average.

The work is currently estimated to cost about $75 million, according to project materials. The state will contribute $47 million of the budget, Measure BB will provide $16 million, Berkeley and East Bay Municipal Utility District will contribute $1 million. There is still a $10 million gap in funding, according to project documents.

“The project will enhance safety at the interchange by replacing unprotected left turns and turning conflicts with a double roundabout,” Caltrans said in a statement. “It will also close the gap in the Bay Trail at the west end of Gilman Street and create a dedicated bike lane from the west end to Fourth Street.”

In addition to Caltrans, the cities of Berkeley and Albany and The Alameda County Transportation Commission (Alameda CTC) are working together to deliver the project.

See a video simulation of a southbound driver on I-80 exiting at Gilman Street and driving into Berkeley.

The work will include sporadic closures of Gilman Street, local streets and freeway ramps, as well as brief overnight closures of I-80 in one direction at a time, said Mara.

See a video simulation of crossing the planned pedestrian/bike bridge.

Funds for the construction will come from Measure BB, a county transportation tax adopted by voters in November 2014. Measure BB, which adds one cent to the county’s sales tax, was an extension of Measure B. It is projected to create $8 billion in revenue through 2045.

Gilman roundabouts
The I-80/Gilman interchange project includes two new roundabouts, a new bridge over the freeway for pedestrians and cyclists, enhanced bike and pedestrian lanes under the freeway, a new section of the Bay Trail, two-way bike lanes along Gilman and a new signal at Fourth and Gilman streets. Image: The Alameda County Transportation Commission.

Improvements to bicycle safety and routes

The project will vastly improve the experience of pedestrians and cyclists traveling between the cities of Berkeley and Albany and the bay, according to Preston Jordan, an Albany City Council member who was also part of the Alameda County CTC committee that developed pedestrian and bicycle improvements. It will make riding on Gilman Street go from a “high-stress” mode of travel to a “low-stress” one, meaning there will be fewer car-bicycle meeting points, he said.

Bikers and walkers will be able to go over or under the freeway. The bike bridge takes many design elements from the bike bridge on the newer section of the Bay Bridge, according to Karen Parolek, an avid cyclist who served on the ACTC committee. She also serves on Berkeley’s transportation commission. There will be two bike lanes, one for each direction, as well as a lane for pedestrians. “There’s plenty of room for everyone, which is great,” she said.

People walking under the freeway also will have an improved experience. Caltrans will be enclosing the open areas under the underpass with concrete walls (space that once held many unhoused individuals). It will add lighting so bright that it always appears to be daylight under the freeway. There will also be two bike lanes at grade and a separate lane for walkers, she said.

Caltrans is also improving bicycle access from the bike bridge to Fourth and Gilman streets, said Parolek. There will be a bidirectional bike path on the south side of Gilman as well as a new signaling system to allow cyclists to cross over Gilman Street and connect with bike paths going to Harrison Park, the Gabe Catalfo soccer fields, University Village in Albany. Currently, there are only bike lanes on Gilman east of Second Street.

The project will also close a gap in the Bay Trail between Berkeley and Golden Gate Fields, said Jordan.

Parolek, who lives right off Gilman Street, said she rides her bike with her children almost everywhere, including to school. One exception is that Parolek never rides with her daughter to play soccer at the Tom Bates Regional Sports Complex on West Frontage Road, even though they live nearby. She doesn’t feel safe riding with her daughter on bikes along Gilman Street with all its entrances and unclear rights of way. Biking down to use the University Avenue bike bridge takes them many miles out of their way.  This project will transform all that, she said.

“I am really excited about how this is going to connect our community to the water,” said Parolek.

Frances Dinkelspiel is co-founder and executive editor of Cityside. Email: frances@citysidejournalism.org.