Los Angeles Regional Connector

The Los Angeles Regional Connector is a 1.9-mile rail alignment that includes a tunnel that will make direct links among three light rail transit lines with passenger connection to the city’s heavy rail subway when it is completed in late 2022.

The contract for construction began in July 2014. Digging for the first of the 1.1-mile twin bore tunnels concluded three years later when the tunnel boring machine (TBM) – known as “Angeli” – broke into the cut-and-cover tunnel trench at 4th and South Flower streets in the city’s downtown. Angeli was taken back to the original starting point at 1st and Alameda streets in Little Tokyo to dig the second parallel tunnel. The TBM then broke into the same trench in January 2018.

The Los Angeles County Metropolitan Transportation Authority’s $1.9 billion Regional Connector project will extend from the Little Tokyo/Arts District Station of the light rail L (Gold) line to the 7th Street/Metro Center Station in downtown Los Angeles, allowing passengers one-seat rides among the A (Blue), E (Expo) and L (Gold) lines and connections to the B (Red) and D (Purple) lines. When completed, passengers will be able to travel from Azusa to Long Beach, or from East Los Angeles to Santa Monica, without transferring trains.

WSP USA has worked on the Regional Connector project since 2008, providing planning, environmental and engineering services, as well as on-site design support during construction. WSP will continue to provide technical support during systems integration and testing as the project works toward the start of revenue operations, scheduled for late 2022.

Riders as well as many local stakeholders will benefit from this “connection,” including several major Los Angeles cultural institutions and districts: the Walt Disney Concert Hall, the Colburn School of Music, The Broad art museum, the Japanese American National Museum, the Downtown Los Angeles Financial District, Little Tokyo, and the Arts District.

The project includes the creation of three new stations – Little Tokyo/Arts District Station at 1st Street and Central Avenue, Historic Broadway Station at 2nd Street and Broadway, and Grand Avenue Arts/Bunker Hill Station at 2nd and Hope streets.

The Regional Connector project includes some “firsts” for Metro. It includes Metro’s first cavern excavated in soft rock by the sequential excavation method for its nearly 300-foot-long rail crossover adjacent to the Historic Broadway Station.

It will also be the first time for Los Angeles transit that high-speed elevators are used for passenger access instead of escalators. Located approximately 100 feet below the surface, the Grand Avenue Arts/Bunker Hill Station will have six high-speed elevators with the hoisting equipment below the elevators, not above, to avoid the visual impact at the station entrance pavilion.

One of the project’s innovations involved the location of the fan plant that provides ventilation for the new tunnel at the junction of the two lines coming into Little Tokyo. Rather than backfilling the TBM launch pit when tunneling concluded, the fan plant was installed in this location, thus avoiding additional excavation and resulting in significant cost savings for the client.

Meeting the commitments made for mitigation of environmental impacts, particularly in the Little Tokyo neighborhood and in close proximity to sensitive stakeholders such as the Walt Disney Concert Hall and the Colburn School of Music, posed challenges that kept the designers on their toes. Noise and vibration impacts of rail operations and environmental justice for construction required extensive efforts to properly establish design-build performance requirements, and to work with the stakeholders and the final designer to ensure mitigation is achieved.

Connecting two existing transit lines that use systems equipment of different designs and ages also requires careful planning that requires expertise and experience in rail transit systems. While the path is complicated, what was set in motion years ago is happening. As the tunneling completed and the underground stations were concreted, WSP is focusing on the transit systems. WSP staff are involved in the process of rail activation and will continue to provide technical assistance post-start of operations.