Geotechnical testing begins for LOSSAN rail realignment

Geotechnical field testing has commenced along portions of the Los Angeles–San Diego–San Luis Obispo (LOSSAN) corridor, specifically within the cities of Del Mar and San Diego, as part of the planned rail realignment project. The testing aims to improve understanding of subsurface soil and rock properties throughout the corridor, which is vulnerable to landslides, erosion, and seismic forces. By integrating new data with prior geotechnical studies, SANDAG hopes to assess which alignments or remediation strategies will best ensure long-term safety, service reliability, and route performance.

One focus of the evaluation includes the possibility of adding a second track between the future special events platform (part of the San Dieguito Double Track Project in Del Mar) and the north end of Sorrento Valley in San Diego. That upgrade would increase capacity, improve service flexibility, and support more frequent train operations.

Testings will take place over several months with each individual site potentially being completed within a couple of days to a few weeks, depending on conditions.