During the weekday peak-hours, the line utilizes articulated buses due to its high ridership volume from Shepherd Parkway.

[4] On January 13, 2001, route W4 was rerouted along Alabama Avenue to serve the new Congress Heights station.

Passengers will be able to alight at stops on South Capitol Street at the Navy′s Firth Sterling Gate, walk through the security checkpoint, and access an internal military shuttle bus which will follow the W9 routing around the base to reach destinations within Bolling Air Force Base and the Navy′s Anacostia Annex.

[6] On June 29, 2003, route W4 was rerouted from Bolling Air Force Base to Anacostia station as a result of the detour.

This was because route W4 was suffering from low ridership with large Portion of the Line in Maryland runs on Congested Roadways, impacting on-time performances with extended run times in Maryland that creates scheduling inflexibility in DC, where overwhelming majority of boardings occur.

[7][8][9] On March 24, 2013, W4 service between Deanwood station and Capital Plaza Mall via Craftsman Circle and Prince George's Hospital was discontinued due to low ridership and to improve on time performance.

Fort Drum and DC Village residents would lose direct service to Anacostia station if the proposal goes through.

[13] During the COVID-19 pandemic, Route W4 was reduced to operate on its Saturday supplemental schedule during the weekdays beginning on March 16, 2020.