Crenshaw LRT

Opportunity

Los Angeles County Metropolitan Transportation Authority’s (Metro) Crenshaw/LAX Transit Corridor currently has high densities of population and employment which are forecast to grow 18% and 20% respectively by 2030, increasing congestion.

The corridor currently has poor connections to Metro’s LRT, and the extension will improve public transit and mobility with connections to existing and new LRT lines. Portions of five jurisdictions are in the corridor — the cities of El Segundo, Hawthorne, Inglewood, and Los Angeles, and portions of unincorporated Los Angeles County.

Solution

As prime consultant, Mott MacDonald is providing advanced conceptual engineering and preliminary engineering services, as well as other support services during construction, in four phases:

• Phase 1. Advanced conceptual engineering documents
• Phase 2. Preliminary engineering, including preparation of FEIR/FEIS technical documents, design-build contract documents, and bid period services
• Phase 3. Design review services during construction as requested by Metro
• Phase 4. Systems activation service support

Three types of stations were considered: 1) underground stations at Crenshaw and Martin Luther King Jr., 2) above-grade stations at Florence/La Brea and Aviation/Century Alternative Site, and 3) at-grade stations at Aviation/Century, Aviation/Manchester, and Crenshaw/Slauson.

Metro’s goal is to lead the transportation industry in maximizing sustainability efforts to the benefit of the people, economy, and environment of Los Angeles County. Mott MacDonald is working closely with Metro to help meet its sustainable targets for the Crenshaw Corridor project.

Mott MacDonald will conduct sustainability workshops to assess design elements appropriate for this project, including architectural treatments, construction materials, and construction processes — and apply them throughout the design process, including LEED silver certification for the vehicle maintenance facility.

Role of Mott MacDonald's visualization team

Due to the project’s route, which runs in a partially lidded trench along the end of Los Angeles Airport’s Runway 25L, the impact on the pilot’s approach is a key concern. Mott MacDonald and the client had to carefully consider both visual appearance and any effects during construction to the imaginary surfaces (buffer zones extending into navigable airspace to avoid obstructions to air navigation) associated with the runway by equipment such as pile drivers.

Our visualization team created visualizations to illustrate a pilot’s eye view of the runway approach and how the zone of construction might interact with the imaginary surfaces. The visualizations were based on the detailed BIM model being created through the design process. We also created an oblique photomontage to illustrate how the existing and proposed infrastructure would link together.

Outcome

Staging plans helped ensure on-time project delivery with no disruption of existing railroad operations. The LRT extension east of LAX Airport was designed as a depressed section or tunnel to accommodate narrow right-of-way and height restrictions and prevent operational impacts on the airport. Advanced visualization techniques helped ensure the safety of aircraft approaches. Outreach to diverse communities provided an opportunity to raise issues of safety, visual quality, cultural identity, construction impacts, and future operations.

Mott MacDonald's design incorporated elements that minimize disruption to the community and promoted community continuity. Noise from vehicle operation will be minimized using one of number of options, including layering crushed rubber beneath the track structure and using continuous welded rail (CWR) to reduce the noise from rail joints.