It’s going to be at least a year until residents can use the Mirada Road Pedestrian Bridge on the California Coastal Trail in Miramar, San Mateo County officials say. Now local officials are working to make the alternative safer in the meantime.
San Mateo County Director of Public Works Jim Porter said the county had been monitoring the bridge for several years before a consultant re-evaluated it last week and advised it be closed immediately because of structural issues.
“The structural steel has rusted to the point where it can no longer take heavy loads,” Porter said. “It’s like bark coming off a tree. It’s simply not safe for people to be on that bridge anymore.”
Now users of the Coastal Trail are being redirected parallel to Highway 1. Porter said his office appealed to CalTrans to put up concrete barriers to separate trail users from highway drivers, but was initially denied. Supervisor Don Horsley and Half Moon Bay City Manager Bob Nisbet will attend a meeting set for Aug. 17 to appeal to CalTrans District 4 Director Tony Tavares to shift traffic and restripe the highway to create a safety corridor, Porter said.
Porter said the yearlong timeline is necessary because winter weather prevents construction until next summer, and because the project is more complicated than just replacing the steel bridge itself. Below the bridge is a World War II-era concrete arch that needs to be removed, and the bluffs on which the bridge stand need to be strengthened. In addition, a sewer line runs adjacent to the bridge.
Porter said the bridge replacement will require a full permitting process through the U.S. Army Corps of Engineers, the California Coastal Commission, the California Department of Fish and Wildlife, and the Bay Area Water Quality Control Board — each of which will include environmental review phases.
Half Moon Bay Mayor Adam Eisen said, although the county is leading the project, the city will help with signage and rerouting logistics.
“We are advocating with the county for a safe and clearly marked detour, and will work in conjunction with the county and Caltrans to ensure this happens,” Eisen wrote in a newsletter to the community.
Porter said he expects construction to begin next summer, and is anticipating three to four months of work before a reopening. He said, while the bridge’s lifespan was clearly coming to an end, county officials did not anticipate its immediate closure.
“We were hoping to get another year out of the bridge,” Porter said.