The opening of the Metro Blue Line in 2004 marked the beginning of Metro Transit's expansion into rail transit, 50 years after the last Twin Cities Rapid Transit streetcars were taken out of service. Several new rail transit projects are either under construction or in planning stages and more are expected to be explored in the near future. Metro Transit will likely be acquiring a significant amount of rolling stock as these new projects move forward. Light rail The Twin Cities region has two active light rail lines, the Blue Line, and the Green Line, and an extension to the Green Line, the Southwest Corridor, is currently under construction. As of 2020, 64 light rail cars are in service and delivery of 27 additional cars is underway. Type I LRVs Metro Transit placed its order for light rail vehicles (LRVs) for the Blue Line with Bombardier in January 2001, originally for 18 cars, but increased in stages to 24 cars by early 2003. Bombardier constructed a full-scale, half-car mock-up of the Minneapolis version of its Flexity Swift design and this was placed on temporary display on a section of completed track on 5th Street, starting on October 30, 2002, to enable Metro Transit to give the city's residents a hands-on preview of the low-floor design several months before completion of the first actual rail cars. The articulated vehicles use a 70% low-floor design, are long and can carry 66 seated passengers and 180 standees. The first light rail vehicle for the Blue Line arrived in Minneapolis in March 2003, and testing of it along the first completed section of the line was underway by June 2003. The line opened on June 26, 2004, with 14 of the 24 Bombardier Flexity Swift LRVs accepted and available for service by then, and all 24 had entered service by the end of the year. In January 2007, the Metropolitan Council announced that three additional vehicles would be purchased, for a total of 27 LRVs on the line. The Blue Line's Type I LRVs are numbered sequentially from 101 through 127. The Flexity Swift vehicle is an articulated design with three car-body sections, referred to as the A, B and C sections. The markings on the ends of LRVs indicate the vehicle number and section. For example, car 114 is marked 114A on one end and 114B on the other end. Vehicle numbers are