The San Diego Association of Governments and the North County Transit District are moving forward on a $31 million project to replace four bridges that cross Los Peñasquitos Lagoon.
The Los Peñasquitos Lagoon Bridges Replacement Project will replace four aging, wooden trestle railway bridges that cross the Los Peñasquitos Lagoon in Torrey Pines with modern, single-track, concrete bridges.
The new bridges will look similar to the Trestles Bridge, near San Onofre State Beach, which was replaced in 2012.
The new bridges will have wider column spans, which are designed to increase tidal flow and help improve the overall health of the Los Peñasquitos Lagoon. The lagoon bridges will not be double tracked as part of this project.
The length of the bridges and their corresponding numbers are: 246.1, 180 feet (northernmost bridge); 246.9, 196 feet; 247.1, 84 feet; and 247.7, 126 feet (southernmost bridge).
Construction is slated to start in the fall and be completed in two years.
Some of the work on the bridges will be conducted during select weekends. All rail service would be temporarily suspended so construction crews can work unimpeded.
People in residences and businesses along the lagoon can expect to hear intermittent construction noise during the project, according to SANDAG.
Piles and columns will be installed as the support structure for the bridges.
A quieter method of constructing piles, called cast-in-steel-shell, will be used. The installation of pre-drilled cast-in-steel-shell piles will help lessen noise for residents near the lagoon.
SANDAG will ensure native habitats are protected and restored during the project.
David Hicks, SANDAG communications manager, said the wooden bridges, built during the 1910 to the 1930s, are being replaced at this time because they have passed their life expectancy of 50 to 75 years.
“This project is a critical part of a larger effort to improve rail infrastructure along the 351-mile Los Angeles-San Diego-San Luis Obispo rail corridor,” Hicks said. “This coastal corridor is the second-busiest intercity passenger rail line in the United States, and is the only viable freight rail link between San Diego and the rest of the nation.”
Every day, more than 70 trains, including the NCTD Coaster, Amtrak Pacific Surfliner and BNSF Railway freight, travel this corridor, according to SANDAG.
The project is designed to maintain compliance with Federal Railroad Administration standards, and meet current and future demand for intercity, commuter and freight rail services.
The bridge replacement project is also consistent with the SANDAG 2050 Regional Transportation Plan.
The project was designed by the North County Transit District and will be managed by SANDAG. Skanska is the contractor and HDR is the engineer of record for this project.
SANDAG received $14 million through a federal grant from the U.S. Department of Transportation under the Transportation Investment Generating Economic Recovery program. These funds will be leveraged with additional money from NCTD and the Federal Transit Administration to pay for the remainder of the $31 million project.
In the coming years, SANDAG has approximately $1 billion in planned improvements for the San Diego County section of the LOSSAN corridor, including a large-scale effort to double track the corridor from Orange County to Downtown San Diego.
To date, half of the county’s LOSSAN rail corridor is double tracked, with approximately 20 rail improvement projects in design or under construction. More than 97 percent of the corridor is expected to be double tracked by 2050.
Other infrastructure improvements include bridge and track replacements, new platforms, pedestrian undercrossing, and other safety and operational enhancements.