It was given high priority by Metro in its long-range plan[2] and had funding set aside for it in Measure R.[3] The draft environmental impact statement was completed in September 2010, selection of a preferred alternative was completed in late October 2010, and the Final Environmental Impact Report was certified on April 26, 2012.

[12] The connector was envisioned as early as 1984 when planning and building the Metro Blue Line and restudied with a through connection in the Pasadena Light Rail Corridor studies in 1989.

The project was revived in 2004, when LACMTA staff initiated a technical feasibility assessment for a potential regional connector.

This study focused on conceptual methods to provide a regional connector and to alleviate potential operational constraints.

[16] In November 2007, preliminary outreach meetings for the Alternative Analysis were held at Central Library and the Japanese American National Museum (JANM).

The results from these meetings were presented to the public in February 2008, including the descriptions of the eight route alternatives identified for analysis, narrowed down to two later in 2008.

At the January 2009 Metro Board Meeting, the Regional Connector was approved and received funding to continue in the environmental study process (Draft EIS/EIR).

A third LRT build alternative was added in February 2010, at the request of Little Tokyo stakeholders (including property, business, and homeowners).

[citation needed] Metro added this alignment in February 2010, after receiving public input on the other two options.

The third station (nearest the Civic Center) was shifted slightly west toward Broadway, to take advantage of redevelopment efforts in the historic core.

[23] The main contractor was finally issued a "Notice to Proceed" in early July 2014;[24] the official groundbreaking for heavy construction on the project was held on September 30, 2014.

This commits Metro to use procedures to ensure that the rumble of trains does not intrude on the sound quality of recordings made in the venues or mar audiences' musical experience within this sensitive stretch of the tunnel.

[26] Two modest, one-story brick buildings had to be demolished since the Little Tokyo/Arts District station will be moved underground and across the street.

The A, E, and L Line trains ran through the newly built tunnel from Long Beach to Azusa and Santa Monica to East Los Angeles.