The Denver City Council took a definitive step on Monday toward making the construction of the East Colfax Avenue bus rapid transit project a reality — one that will completely reshape Denver’s best-known east-west arterial street. The project will stretch from Denver’s Union Station east to the Regional Transportation District’s rail station near Colfax and Interstate 225 relying on a network of high-frequency, quick-loading buses to increase mass transit reliability along the busy corridor.