North Torrey Pines Bridge to become quake-proof

Project to keep bridge stable for additional 50 years

By Jonathan Horn


The North Torrey Pines Bridge has stood long and narrow for the last 75 years. To ensure that it remains safe and sturdy for at least the next half-century, the city of Del Mar is planning to seismically retrofit the 553-foot-long and 49-foot-wide structure.

“The North Torrey Pines Bridge is one of Del Mar’s treasures and is one of the few remaining examples of cast concrete bridges remaining along the California coast,” Del Mar Mayor Crystal Crawford wrote in a column published in the Del Mar Times. “The seismic retrofit of the bridge will be the largest capital project undertaken in the city’s history.”

The project, which will cost roughly $37 million, will be 80 percent paid for with federal highway funds, with the rest by city money. Environmental reviews are complete, and Del Mar will begin sending out bids to contractors in the near future.

Once construction begins, the bridge will remain open to two-way traffic, with the exception of some nighttime closures.

“It’s clearly a structure that does not meet current criteria,” said Frieder Seible, dean of the Jacobs School of Engineering at UCSD, who the city of Del Mar hired as a consultant. “The issue with the Del Mar bridge is that while yes, it is substandard in terms of seismic design right now, there are so many other things wrong with it.”

Seible said the bridge’s guard rails would not keep a car from falling off in case of a bad accident. Improving that kind of infrastructure is also part of the project, as well as replacing the entire concrete deck where cars drive.

“If there is a significant seismic event, it may fail,” said David Scherer, Del Mar public works director. “So the project is a combination of making it a seismically stable structure so if there is a big earthquake from the Rose Canyon fault, the bridge would stand, and then further to improve it to a point to last fifty years.”

The historic look of the North Torrey Pines Bridge, which was designated a historic landmark in 1996, will be maintained. There are no plans to add lanes to the bridge.

“They really don’t want to feed a larger amount of traffic on the coast roads because most are one lane functionally,” Scherer said, referring to city of San Diego developers.

The bridge crosses the city limit between Del Mar and San Diego, but in 2000, the cities agreed to transfer the entire bridge to Del Mar in order to undertake the seismic retrofitting project.

“I drive over that bridge everyday twice,” Seible said when asked if he is apprehensive about crossing the bridge each day during his commute to UCSD. “Usually the traffic goes quite slow anyways, but I wouldn’t drive any faster.”

A public presentation where a preview of the project will be discussed is scheduled for Sept. 10 from 5 to 7 p.m. at Del Mar City Hall.

Seismic retrofit project

  • Public presentation and preview
  • 5 to 7 p.m., Sept. 10
  • Del Mar City Hall