The 14th Street Line, designated Routes 52, 54, is a daily bus route operated by the Washington Metropolitan Area Transit Authority between Takoma station of the Red Line of the Washington Metro and L'Enfant Plaza station (52) of the Blue, Yellow, Orange, Green, and Silver lines of the Washington Metro or Metro Center station (54) of the Red, Blue, Orange, and Silver Lines of the Washington Metro.

The 14th Street Line is one of the most heavily used routes in the Metrobus system; about 15,000 riders use it on a typical weekday.

Route 52 only serves Takoma station during the early mornings and late nights daily, terminating at 14th Street and Colorado Avenue NW during most of the day.

On school days, some Route 54 trips run north from 14th & Aspen Streets NW or Reeves Center.

On September 21, 1895,[4][5] the Rock Creek Railway bought the Washington and Georgetown and changed its name to the Capital Traction Company.

The Love system transmitted electricity through a set of trolley wheels running on underground conduit rails.

By the 1920s, cars were turned at four northern terminals: Park Road, Decatur Street, Colorado Avenue, and Takoma (via the Washington and Maryland Line).

Routes 50 and 54 were acquired to run by buses under DC Transit when streetcars began to phase out.

Routes 50 and 54 operated from Takoma and Bureau of Engraving and Printing (50) and Navy Yard (54) primarily running along 14th Street.

[12] On February 6, 1978, routes 50, 52, and 54 were rerouted to serve the newly opened Takoma station in order to connect riders to the Washington Metro.

But it was also proposed to improve the frequency of buses between Takoma station and 14th Street and Colorado due to high ridership volume.

WMATA would also adjust the weekday schedule to coordinate local route 52 and 54 service with a proposed new MetroExtra limited-stop route 59, serve the Wharf, and decrease the time between buses to Takoma station.

[20] On June 13, 2017, the DC Council and DC Mayor Muriel Bowser approved WMATA's FY2018 budget (a $1.2 million budget) which includes the new limited stop route and reconstructed service along 14th Street.

[23] This was due to the following reasons:[24] About 4,800 riders board Route 52 or 54 local service at stops south of 14th Street & Colorado Avenue that are not served by route 59, which would see a 50% reduction in frequency of local service.

This is approximately 38% of the total 12,800 riders that board all 52, 54 buses on an average weekday according to WMATA.

[25][26][27][28] During the COVID-19 pandemic, the line was reduced to operate on its Saturday supplemental schedule during the weekdays beginning on March 16, 2020.

[30] On March 21, 2020, weekend service on the 52 became suspended and Route 54 was reduced to operate every 30 minutes.