In February 2013, Southern California Association of Governments (SCAG) completed an Alternatives Analysis (AA) Study that analyzed opportunities for a 34-mile long study area from Los Angeles Union Station to the City of Santa Ana in Orange County. In addition to a No Build and Transportation Systems Management (TSM) alternative, the AA evaluated six build alternatives along various alignments: Bus Rapid Transit (BRT), Street Car, Light Rail Transit (LRT), Diesel Multiple Unit (DMU), High Speed Rail, and low-speed Magnetic Levitation Train. SCAG recommended that further study be conducted on No Build, TSM and LRT along two alternatives (West Bank Option 3 and East Bank).
In July 2015, the Technical Refinement Study (TRS) conducted by Metro built upon the analysis from the SCAG AA, focusing on the Los Angeles County segment of the Pacific Electric Right-of-Way/WSAB corridor. The TRS provided updated capital cost and ridership forecasts, as well as additional analysis on specific challenges identified in the SCAG AA, including:
- Feasibility of Union Station as a northern terminus - feasible
- Refinement of northern alignment options – four new alignments identified
- Station relocation and realignment in the City of Huntington Park – station relocation feasible and realignment not recommended
- Construction of a new station on the Metro Green Line - feasible
- Feasibility of southern terminus station in the City of Artesia - feasible
The Gateway Cities Council of Governments (COG) , which represents 27 cities in Southeast Los Angeles County, developed a Strategic Transportation Plan (STP) that unified the vision for all elements of the transportation system, including the WSAB transit component. The STP developed local resources and builds on previous transportation studies to create an integrated transportation system for the 27 cities in the Gateway Cities Subregion. The STP enables individual cities to understand how their transportation plans and decisions impact neighboring cities and vice versa — how individual cities fit within the larger region.