L Line (RTD)

Proposed extension

The Central Rail Extension Mobility Study Final Report^[5] proposed that the D Line stations from 20th & Welton to 30th & Downing and future extension stations be operated on an independent route. This route would operate from the downtown loop to a new terminus created by sharing the A Line's 38th & Blake station.^[6] Former D Line riders would have to transfer to the new L Line as the D Line's new northern terminus would be the downtown loop (nominally 18th & California station). The 14th & California station closed in 2004 could be restored to support the L Line at the Convention Center, allowing for transfers to Theatre District–Convention Center station.^[5] RTD's board of directors approved the introduction of the current shorter version of the L Line with the January 14, 2018 service changes. The L Line uses existing track between 30th & Downing station and the downtown loop.^[7]

Beginning on May 26, 2024, the L Line was suspended, as part of Phase 1 of the Downtown Rail Reconstruction Project,^[8] which involves rebuilding some of the oldest sections of RTD track.^[9] However, on August 29, that phase was completed,^[9] and on September 29, the D, H, and L Lines returned to service.^[10] Service on the L Line was temporarily suspended again on August 31, 2025 for Phase 3 of the Downtown Rail Reconstruction Project. Service resumed on January 4, 2026, after the completion of Phase 3.^[11]