The routing was approved for BRT development in 2012 by C-Tran, the Vancouver City Council, and the Federal Transit Administration and construction began in August 2015.

The Southwest Washington Regional Transportation Council (RTC) began studying high-capacity transit for Vancouver and Clark County in 2008, and determined that bus rapid transit would be viable on four main corridors: Highway 99, Fourth Plain Boulevard, Interstate 205, and Mill Plain Boulevard.

[4] The Fourth Plain corridor had been served by local routes 4 and 44, the two busiest in the C-Tran system, which continued to northern Portland, Oregon.

[5] Design concepts for a Fourth Plan bus rapid transit service were presented in 2011 and 2012,[6] and a locally-preferred alternative was adopted by C-Tran, the Vancouver City Council, and RTC in 2012.

[7] On November 6, 2012, C-Tran placed a 0.1 percent sales tax increase on the general election ballot to fund a light rail extension from Portland to Downtown Vancouver via a new bridge, as well as operating costs of the Fourth Plain bus rapid transit project.

[16] C-Tran held a community celebration on January 7, 2017, including a street fair and preview rides attended by 200 people.

[25] The Green Line is also planned to be extended east into Orchards and south along Northeast 162nd Avenue to Fisher's Landing Transit Center, a major regional hub near the Columbia River, by 2026.

[9][30] Stations consist of a 50-foot-long (15 m) platform that is raised for level boarding, and includes shelters and windscreens, ticket vending machines, real-time arrival signs.

[36] Hop card readers were installed at all Vine stations and used for the beta testing period prior to the public launch.