Skip to Content
Streetsblog San Francisco home
Streetsblog San Francisco home
Log In
Bicycle Safety

The Sorry State of Caltrans’ Dumbarton Bridge and Bay Trail

Debris on Dumbarton Bridge
Garbage and debris on the Dumbarton Bridge commonly reduce the usable width of the bridge's mixed-use path from 8 feet to 6 feet.

The Dumbarton Bridge, which connects Menlo Park in southern San Mateo County with Fremont in the East Bay, remains the only bridge that allows bicyclists and pedestrians to cross the San Francisco Bay from east to west, with an eight-foot wide path on its southern side. From the bridge, the path continues for three miles along Bayfront Expressway (Highway 84) through Menlo Park to Marsh Road. It's an important biking and walking connection for both commuting and recreation.

Longitudinal cracks on the Bay Trail.

Poor maintenance of the bridge path and Bay Trail by Caltrans, however, continue to discourage use. The bridge path is not swept often enough to keep it free of glass and other debris, which reduces the usable width of the path from the minimum eight feet required by Caltrans' own Highway Design Manual. Occasionally, large objects such as car bumpers and plastic buckets litter the path. From mid-May to mid-June, large piles of highway debris blocked a two-foot section of the path. The culprit? After the roadway was cleaned, the garbage that had accumulated there was dumped onto the car-free path. Though the large items littering the path have been removed, glass shards and dirt remain.

John Fox, who has commuted by bike from Fremont to Stanford University for the last 13 years, finds the bumpy, pothole-filled conditions of Marshlands Road, used to access the bridge from the East Bay, a greater challenge. "That road is horrible, it's like a cheese grater," he said. "In the winter time a lot of us ride until dark, and then it's pretty dangerous."

Bay Trail sunken utility access panels
Sunken utility access panels create a hazard for both cyclists and pedestrians and reduce the usable width of the Bay Trail in Menlo Park.

The Bay Trail west of the bridge presents its own hazards due to poor maintenance. Several utility access panels have sunken below the level of the path as the pavement has expanded slowly over time due to heat. One such panel now lies three inches lower than the path, resulting in an edge that can catch a bicycle's front wheel and presents a tripping hazard for pedestrians. Caltrans' solution for the past several years has been to simply place orange warning cones on the access panels.

Weeds overgrowing the Bay Trail in Menlo Park
Uncut weeds narrow the path, eat away at the path's paved edges, and cause cracks to expand faster.

Mike Jacoubowsky, who works at Chain Reaction Bicycles in Redwood City and describes the Dumbarton Bridge path and the intersections along Bayfront Expressway as "paved with glass," believes the paths would attract a lot more use if properly maintained.

"The potential of appropriate and safe cross-bay cycling is huge," he said. "But not adequately maintaining and enhancing [the Dumbarton Bridge crossing] has limited its usefulness drastically."

So what will Caltrans do to make the path more usable? "The weeds are mowed three times per year, and the cracks will be repaired within a month and a half," said Caltrans Public Information Officer Gidget Navarro. But the path on the Dumbarton Bridge isn't swept because it "cannot accommodate the size and weight of the sweeper," she added, and the utility access panel currently covered by the large steel plate is a PG&E project, not Caltrans.

Stay in touch

Sign up for our free newsletter

More from Streetsblog San Francisco

See all posts