The line opened with 28 stations on November 29, 2009 as "Swift", becoming the first bus rapid transit system in the state of Washington and costing $29 million to construct.

The Blue Line was extended south from Aurora Village to Shoreline North/185th station in September 2024 following the opening of the Lynnwood Link light rail project.

The Blue Line, designated internally as Community Transit Route 701,[2] begins at Bays G and H at the south end of Everett Station.

[4] Buses travel south in general purpose lanes on Evergreen Way, passing over State Route 526 north of Casino Road Station.

[5] The road continues southwest as State Route 99 into the unincorporated community of Lake Stickney, where the Blue Line stops at Airport Road Station, a transfer with the Green Line to the Boeing Everett Factory and Mill Creek,[6] and Lincoln Way Station north of an interchange with State Route 525.

[7] The line enters the city of Lynnwood and moves into business access and transit (BAT) lanes at 148th Street Station,[8] where a queue jump signal for northbound buses was installed in 2012.

[11] The line crosses over State Route 104 and enters the city of Shoreline in King County, before it turns east onto North 200th Street and reaches its southern terminus at Aurora Village Transit Center Bay 9.

[16]: 4 [17] The platform and shelter also include a roadside beacon that is lit at night, graffiti-resistant weather barriers, two Parkeon ticket vending machines,[18] two ORCA card readers, and a next bus arrival sign.

Buses stop at all stations,[19] are allowed a dwell time of 10 seconds, and use curb bumpers to guide them closer to the platform.

[13][14][23] The Blue Line runs at a headway of 10 minutes from 6 a.m. to 7 p.m. on weekdays, its highest level of service with five buses per hour per direction.

[59] In December 2005, the CT Board of Directors approved an accelerated planning schedule for a bus rapid transit project, to cost an estimated $15–20 million, and to begin service as the first such system in the Puget Sound region in 2008.

The agency envisioned real-time arrival signs at stations, and transit signal priority, among other improvements over existing bus service.

[61][62] The following year, CT purchased its fleet of 15 hybrid diesel-electric buses from New Flyer, at a cost of $879,028 per vehicle, to be paid for with state and federal subsidies.

[64][65] A groundbreaking ceremony for the first Swift station, located at Airport Road in south Everett, was held on December 3, 2008, and was attended by Community Transit CEO Joyce Eleanor, U.S.

[78] The successful launch of Swift, which saw ridership grow to 3,000 daily boardings in its first five months of service, earned Community Transit a Vision 2040 Award from the Puget Sound Regional Council in May 2010.

[28][29] The stations were paid for by $1.6 million in regional mobility grants from the Washington State Department of Transportation to Everett Transit, awarded in May 2009.

[17] In 2012, a queue jump signal was installed northbound at the north end of the BAT lanes at 148th Street, allow Swift buses to merge into traffic.