Project Profile: San Diego’s Mid-Coast Trolley Extension

The Mid-Coast Trolley project is an 11-mile (17.7 km) extension of the San Diego Trolley’s Blue Line, engineered to enhance regional mobility and provide a direct public transit connection to the high-density University City corridor. This profile details the technical specifications, strategic importance, and implementation of this critical light rail infrastructure project. The extension was designed to integrate directly with major employment, healthcare, and educational centers, thereby alleviating significant congestion on the parallel Interstate 5 corridor.

Project Fact Sheet

Technical Specifications

The Mid-Coast Trolley extension commences north of the Old Town Transit Center, utilizing an existing railroad right-of-way that runs parallel to Interstate 5. The project involved the construction of nine new stations, including elevated and at-grade structures, designed to serve key destinations such as the VA Medical Center and the University of California, San Diego (UCSD). Due to the region’s seismic activity, extensive geotechnical analysis and fault studies conducted by Kleinfelder were integral to the design, ensuring all structures adhere to stringent seismic resilience standards. To support the expanded service, the project’s rolling stock was augmented with 45 Siemens S700 light rail vehicles (LRVs), known for their low-floor design and energy efficiency. The line terminates at the Westfield UTC transit center, a major regional commercial hub.

Key Takeaways

• Strategic Corridor Connectivity: The extension provides a one-seat ride from the U.S.-Mexico border to the University City area, directly connecting residential communities with major economic and educational centers like UCSD and the Sorrento Valley biotech hub.
• Congestion Mitigation: By offering a reliable alternative to the chronically congested I-5 freeway, the project was designed to absorb an estimated 21,000 additional daily transit trips, significantly reducing vehicle miles traveled.
• Robust Funding Model: The project demonstrates a successful large-scale transit funding strategy, combining a 50% contribution from the Federal Transit Administration’s (FTA) New Starts grant program with long-term local financing from the TransNet half-cent sales tax.

Frequently Asked Questions (FAQ)

When did the Mid-Coast Trolley open?

The Mid-Coast Trolley extension officially opened for passenger service in November 2021. The new service integrated seamlessly into the existing UC San Diego Blue Line, creating a continuous route from San Ysidro to University City.

Who built the Mid-Coast Trolley extension?

The primary construction contract for the Mid-Coast Trolley extension was awarded to Mid-Coast Transit Constructors. This entity is a joint venture composed of three leading infrastructure firms: Stacy and Witbeck, Skanska USA, and Herzog Contracting Corporation.