Mid-Coast Trolley Project, San Diego, California, United States of America


San Diego trolley

The Mid-Coast Trolley project is a proposed 17.7km-long extension to the existing Blue Line, which is a light rail system in the San Diego Trolley system in the US. The new extension will connect Old Town, the University of California, San Diego (UCSD), and Westfield UTC.



Ground was broken for the California high-speed rail project in Fresno in January 2015.


The priority transit project is being implemented to increase the capacity of the light rail transit corridor, improve the mobility in the area and minimise the congestion on freeways and roadways.

The extension will also serve the growing commuter traffic in the region, as the density of population and employment in the area is expected to increase by 19% and 12% respectively by 2030.

Mid-Coast Trolley project route and station details

The SANDAG board of directors approved the Mid-Coast Trolley route, which concluded to be the locally preferred alternative (LPA), in July 2010.

The proposed extension route originates just to the north of the Old Town Transit Centre and continues along the existing railroad right-of-way and beside the Interstate 5 (I-5) to Gilman Drive. It will intersect the I-5 twice at just south of Nobel Drive and near Voigt Drive, before reaching the UCSD neighbourhood, Genesee Avenue and the Westfield UTC transit centre.

New stations will be built at Tecolote Road, Clairemont Drive, Balboa Avenue, Nobel Drive, VA Medical Centre, Pepper Canyon serving UCSD west campus, Voigt Drive, which serves UCSD east campus, Executive Drive, and the Terminus Station at the Westfield UTC.

Mid-Coast Trolley project construction

The SANDAG board of directors gave environmental clearance to Mid-Coast Corridor Project in November 2014. Pre-construction activities currently underway include acquisition and utility relocation.

Pre-construction activities began in early 2016 and major construction is scheduled to begin in fall 2016, while operations are scheduled to begin in 2021.

Contractors involved

Mid Coast Transit Constructors, a joint venture of Stacy & Witbeck, Skanska USA and Herzog Contracting Corporation, was appointed as the general contractor for the project in May 2014.

"The new extension will connect Old Town, the University of California, San Diego (UCSD), and Westfield UTC."

Kleinfelder provided geotechnical recommendations, fault study investigation, seismic design and hazmat environmental services to the project.

In September 2016, Mid-Coast Transit Constructors received a $921.8m contract for construction of the project. Parsons Brinkerhoff, Kimley Horn and HDR are responsible for designing the Mid-Coast Trolley project.

Financing for the LRT extension

The estimated cost for the transit project is $1.7bn, excluding financing costs. The full funding grant agreement (FFGA) of the FTA's New Starts programme will generate 50% of funds for the project. The remaining funds will be generated from the region's TransNet half-cent sales tax for transportation.

TransNet will also provide operating funds for the extension until 2048.

Benefits of the Blue Line extension

The Mid-Coast Trolley project will provide commuters with a transfer-free ride from the international border and residential areas south of Downtown San Diego to University City. It is expected to be used by an additional 21,000 daily commuters a day.

The extension will provide improved transit connections to University City, which is an busy employment centre and densely populated area similar to Downtown San Diego. It will also ensure efficient trolley service throughout the Mid-Coast corridor.