The San Diego Coaster in Del Mar on Sept.19, 2022.
The San Diego Coaster in Del Mar on Sept.19, 2022. / Photo by Ariana Drehsler

A plan to move the train tracks that run along Del Mar’s bluffs into an underground tunnel is moving forward thanks to a $300 million state grant.  

That’s a starting point for a $3 billion project that’s a major piece of the region’s $160 billion long-term plan for the region, managed by the San Diego Association of Governments. The new tunnel would run 80 feet underground, and nearly a mile inland from their current, precarious location, but would take until at least 2035 to be completed. 

The plan also includes double tracking the route between the San Dieguito Lagoon and Sorrento Valley, a process that will add a second set of rails for trains to pass each other, which would allow more frequent service on the busy corridor. 

The bluffs have been slowly eroding for years, causing multiple bluff collapses, and becoming a growing threat to both beachgoers and crucial regional infrastructure. As the bluffs have continued to grow more fragile, relocating the train tracks has become critical, SANDAG and Del Mar officials agree. 

The Concern 

A section of the train tracks in Del Mar on Sept.19, 2022.
A section of the train tracks in Del Mar on Sept.19, 2022. / Photo by Ariana Drehsler

In 1941, heavy rains caused a bluff collapse that resulted in “the great train wreck of 1941.” A northbound freight train crashed onto the Del Mar beaches below, causing three fatalities. 

In 2021, a century-old retaining wall collapsed, fortunately not while a train was passing by, but it shut down the rail corridor for weeks. 

Sea level rise and a faster rate of coastal erosion have caused multiple smaller bluff collapses over the years. The bluffs are now eroding at an average rate of 4 to 6 inches per year Danny Veeh, a senior planner at SANDAG, said at the Sept. 9 meeting. 

The LOSSAN corridor, which is the 351-mile railroad route from San Diego to Los Angeles and San Luis Obispo, serves more than 8 million passengers per year, making it the second busiest rail corridor in the U.S. 

Almost two miles of that corridor runs seaside along the Del Mar bluffs. 

The Alternative 

A “Unstable Cliffs Keep Off” sign can be seen near the train tracks in Del Mar on Sept.19, 2022.
A “Unstable Cliffs Keep Off” sign can be seen near the train tracks in Del Mar on Sept.19, 2022. / Photo by Ariana Drehsler

Some residents have raised concerns about the potential impacts that underground trains will have on the surrounding community, like whether they might be near one of the tunnel’s ventilation shafts, whether they will be able to feel vibrations from trains traveling beneath their homes, and how close they might be to one of the tunnel’s portals. 

Veeh said these concerns will be studied in the coming months. The transportation agency and Del Mar’s elected officials maintain that this is the most cost-effective option that will solve the growing threat and preserve Del mar’s beaches. 

Since 1996, SANDAG and the North County Transit District have completed a series of stabilization projects along the coastal bluffs between Coast Boulevard and Torrey Pines State Beach hoping to prolong the viability of the corridor. 

These have each cost tens of millions of dollars and resulted in soldier piles, drainage ditches, seawalls and retaining walls that many Del Mar residents and city officials argue are restricting beach access and changing the character of Del Mar’s beaches. 

In July, the California Coastal Commission approved the next phase – a three-year, $68 million series of projects to further stabilize the train tracks despite objections from the city of Del Mar. This phase requires more than 2,000 feet of additional seawalls to be installed. 

But stabilization projects like these can prolong the train route until officials can reach a permanent solution. 

The Timeline 

Surfers walk over the train tracks in Del Mar on Sept.19, 2022.
Surfers walk over the train tracks in Del Mar on Sept.19, 2022. / Photo by Ariana Drehsler

SANDAG is currently in its planning and public outreach phase, which will soon include choosing the particular route the project will ultimately use. 

The agency considered five potential inland routes in 2017, all with tunnels, and in 2021 narrowed those to two options — underneath Camino Del Mar or underneath Del Mar heights through Crest Canyon. Both routes would extend south into the city of San Diego. 

Planners expect to finish their design work by 2026, with construction expected to begin by 2028. By 2035, SANDAG hopes to have the project completed and open to the public. 

The $300 million recently awarded to the agency by the state will fully fund SANDAG’s next steps – preliminary engineering, technical studies and biological surveys, all necessary studies to assess the project’s environmental impacts. 

The funding comes as part of California’s $308 billion state budget signed by Gov. Gavin Newsom in June. But it’s unclear, for now, where the remainder of the project cost will come from. SANDAG officials expect regional transportation projects to compete for recently approved federal infrastructure funds, but metropolitan areas typically win those dollars with the help of local funding from tax measures. The region’s existing transportation tax, TransNet, is mostly tapped out. 

In Other News

Tigist Layne is Voice of San Diego's north county reporter. Contact her directly at or (619) 800-8453. Follow her...

Join the Conversation


  1. Good morning, I am deeply concerned for the Del Mar and carmel valley area of residents this will effect. Noise, more air pollution , home value, disturbance in everyday life just for commuters. This area has endured one paseo and what it brought. That’s one thing, but the train sabotages peace, and community. I vote no. Solution, for a few short miles , train stops and a coffee station , fast bus or trans route to next pick up of train. Leave the communities alone. I will personally will su the city. I have no place to go. I am in my sixties Where am I going to go. )-:

  2. This will only cause catastrophic, loss in value, Noise, vibration, soot and damage to homes built in the Del Mar carmel valley area. The city will be facing law suits for years.

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