Oxon Hill–Fort Washington Line

On December 28, 1991, route P18 was diverted along Firth Sterling Avenue to serve Anacostia station when it opened.[2]

On January 13, 2001, route P19 was rerouted between Fort Washington and Oxon Hill Park & Ride lots to operate via East Swann Creek, Fort Washington, Livingston and Oxon Hill Roads. Routes P17 and P18 were not affected.[3]

In 2014 during WMATA's FY2015 budget, WMATA proposed to reroute P18 to Southern Avenue station via Southern Avenue in order to improve connectivity in southern Prince George's County and to Shifting to Southern Avenue Station will help alleviate crowding at Anacostia station. Another option was to transfer the P18 to TheBus and being rerouted to Southern Avenue station.[4]

Also WMATA proposed to eliminate existing boarding and alighting restrictions and instead create a limited stop segment between the Oxon Hill Park & Ride and South Capitol & O Streets for routes P17 and P19 because the existing boarding and alighting restrictions are confusing for passengers and operators and creating a limited stop segment would preserve the “express” nature of the route in a more easy to understand way.[4]

On June 21, 2015, route P18 was diverted along Southern Avenue to serve Southern Avenue station discontinuing service to Anacostia station. Routes P17 and P19 also discontinue the boarding and alighting restrictions and instead had a limited stop segment created between the Oxon Hill Park & Ride and South Capitol & O Streets.[5][6]

During WMATA's FY2018 budget, WMATA proposed to either eliminate the Oxon Hill–Fort Washington Line or discontinue service to Downtown DC being rerouted to Southern Avenue station. WMATA would also charge the local fare for routes P17 and P19 as express service would be discontinued if it was rerouted to Southern Avenue. This was in order to reduce costs and it has a high subsidy per rider. Performance measures for WMATA goes as the following:[7]

The line would later be saved in 2017.[8]

Beginning on June 25, 2017, service to Downtown DC was discontinued. Route P19 was rerouted along Southern Avenue to serve Southern Avenue station alongside route P18 keeping its same routing between Oxon Hill Park & Ride and Fort Washington Park & Ride. Route P17 was discontinued and replaced by route P18 which added weekday peak hour service in both directions. P19 would still operate in the weekday peak-hour direction during the changes.[9]

Express fares for route P19 was also discontinued and the limited stop segment was also discontinued with all trips becoming local.[10]

Beginning on August 7, 2017, in response to customer feedback, routes P18, P19, and W14 implemented a new limited stop segment along Southern Avenue between Southern Avenue station and Indian Head Highway serving only three stops in each direction. Local service is provided by routes A6, A7, D12, D13, D14, NH1, and P12.[11]

On September 26, 2020, WMATA proposed to eliminate all route P19 service and replace them with route P18 due to low federal funding. Route P19 has not operated since March 17, 2020 due to Metro's response to the COVID-19 pandemic.[12]