Now that state officials have finalized plans to add a suicide barrier to the San Diego-Coronado Bridge starting in October, they are shifting their focus to a more expensive retrofit of the piers supporting the bridge.
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That retrofit, which has a cost estimate of $350 million to $450 million, aims to make the 57-year-old bridge safe during earthquakes and better prepared for ship collisions like one that took down a major bridge in Baltimore two years ago.
State officials say keeping the Coronado Bridge physically sound is crucial to the region and the nation because the bridge’s navigational channels are used by Navy aircraft carriers and cargo ships from the National City Marine Terminal.
It’s also a crucial traffic artery, moving more than 70,000 vehicles a day between San Diego and Coronado, including Naval Base Coronado and two other Navy bases in the city.
The bridge’s 22 piers were seismically retrofitted from the water upward in 2002, but the underwater infrastructure supporting the piers hasn’t been renovated or upgraded since the bridge opened to traffic in 1969.
Caltrans recently got far enough into the design process for the retrofit that the agency is now launching its environmental analysis of the project and expects to release a draft environmental study in early 2027.
After years of analysis, Caltrans has decided to weave strong micropiles into the 499 aging piles that now support the bridge’s piers, said Allan Kosup, chief deputy director of Caltrans District 11 in San Diego and Imperial counties.
The retrofit will also include adding new fenders, called dolphins, to the piers to make them more resilient to ship collisions. In 2024, a cargo ship crashed into Baltimore’s Francis Scott Key Bridge and caused a partial collapse.
Speaking to the state Transportation Commission last week in San Diego, Kosup stressed that another reason for the fenders is that Navy ships have also gotten larger since the bridge opened.
He said “it’s sort of questionable” whether the existing pier fenders are adequate to protect the columns that hold up the bridge from the impact of large Navy ships.
Kosup said a key challenge of determining the right ways to retrofit the bridge is the need to maintain the width of two navigational channels on the bridge’s eastern side near San Diego.
The retrofit is needed primarily because many of the 499 piles that hold up the piers have micro-cracks.
“Over time, salt water gets in there and can corrode the rebar,” Kosup said. “We’ve been monitoring it over time.”
He said Caltrans decided in 2016 to do a deeper analysis of those piles, including something called replica pile testing, with help from UC San Diego.
“The conclusion was that we really need to move forward with a retrofit,” Kosup said.
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Options considered during the analysis included drilling holes in the existing piles and adding more steel inside, or widening the pile caps so more piles could be added on the outside.
“Those alternatives proved to be costly and have constructability concerns,” Kosup said.
Instead, Caltrans will add micropiles in between the existing piles, he said.
“In the last year, we’ve really firmed our perspective on what’s the best way to restore these piles,” Kosup said.
Caltrans also recently completed something called a navigational clearance determination for the proposed designs.
Kosup said Caltrans plans to ask the Transportation Commission for roughly $40 million in either 2028 or 2029 to finalize the designs. Once those are complete, Caltrans will ask for construction money in the early 2030s, he said.
“The range of alternatives on the construction side would be about $350 million to $450 million,” Kosup said.
Roughly $11 million has been spent so far, he said.
Charles Bradshaw, community plans and liaison officer at Naval Base Coronado, said the bridge preserves vital defense access as part of the strategic highway network.
He commended Caltrans for the preliminary designs and for working closely with the Navy.
“The designs of the project were made in a manner that preserves safe passage of the ships beneath the bridge,” Bradshaw said.
Last Friday, Caltrans cleared the final hurdle facing a new suicide barrier for the iconic bridge when the Transportation Commission unanimously approved $162 million for the long-awaited addition.
The approval will allow crews to break ground this fall on the roughly two-year project, erecting an 8-foot-tall mesh-steel barrier on both outer edges of the bridge to make it less vulnerable to suicide attempts.
The barrier is expected to sharply reduce such attempts on the bridge, which Caltrans says is the No. 2 bridge in the nation for suicide attempts after the Golden Gate Bridge.
Fewer suicide attempts will also mean fewer lengthy bridge closures, which affect national security and require drivers to take a 23-mile detour through Imperial Beach and up the Silver Strand to get from San Diego to Coronado.
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