The D Line's northern terminus is in downtown Denver, at 18th Street. On trips from Littleton, the line runs along 14th Street and California Street before reaching the northern terminus; on trips leaving downtown, the line goes along Stout Street. Then the line follows Stout Street and Colfax Avenue, then runs along the Colorado Joint Line. The southern terminus is at Mineral Avenue in Littleton.[2]
The line previously went as far north as Five Points, but was truncated to downtown with the commencement of LLine service in January 2018.
The 2004 voter approved FasTracks plan will add 2.5mi (4.02km) to the D Line. This will bring the line's southern terminus to a new station with 1,000 parking spots at C-470 and Lucent Boulevard in Highlands Ranch.[3] An environmental evaluation for the station was completed in 2010.[4] Plans for the design of this station were made along with the environmental evaluation, however station construction has received insufficient funding. There is no clear date for when construction is slated to begin. Additionally, the 2010 evaluation suggested an intermediate station at C-470 and South Erickson Boulevard, which was not a part of the original FasTracks plan.
FasTracks also includes the addition of an infill station[5] next to West Bates Avenue in Englewood in between the existing Evans and Englewood stations, however no progress on the station has been made since FasTracks' approval in 2004.