The Riggs Road Line, designated as Routes R1 & R2, is a daily bus route operated by the Washington Metropolitan Area Transit Authority between Fort Totten station of the Red and Green Lines of the Washington Metro & Adelphi (R1) or Calverton (R2).

Route R1 and R2 provides service along Riggs Road between Fort Totten station and Adelphi or Calverton.

On December 11, 1993,[4] the R8 Metrobus Route was discontinued and replaced by the R2 Metrobus Route, which was rerouted to operate between Fort Totten station and Great Oaks Center (Calverton), via the Prince George's Plaza Metro Station and Prince George's Plaza Shopping Center.

Prior to this time, the R2 Metrobus Route operated as part of the Queens Chapel Road Line between the Brookland - CUA Metro Station and Great Oaks Center (Calverton).

During this same exact time, WMATA also created the brand new R1 and R5 Metrobus routes, to operate as part of the Riggs Road Line.

R5 would operate on nearly the exact same routing as R2 between the Fort Totten Metro Station and Calverton, only with the exception of skipping R2's diversion off of Riggs Road onto East - West Highway to serve the Prince George's Plaza (now Hyattsville Crossing) station and Prince George's Plaza Shopping Center, during weekday rush hour/peak period times only.

[4] On the other hand, R1 would only operate on shortened trips between the Fort Totten Metro Station and Adelphi during weekday rush hour/peak period times only.

[2] On May 15, 2003, the original bus bays inside Prince Georges Plaza Shopping Center, were demolished in order to build a new Target store.

[13] If the proposals are made, the R2 would provide a more direct route to Calverton or Fort Totten for customer convenience with the R1 being discontinued due to it being a duplication of the R2.