Pershing Drive–Arlington Boulevard Line

The 4A and 4B operate from Four Mile Run Division on various schedules. The 4A only operates during rush hours, while the 4B operates on a daily schedule. The 4A does not serve the neighborhoods of Courthouse, Lyon Park or Buckingham, but operates the entire route via Arlington Boulevard. The 4B runs through the neighborhoods in Arlington County, where the 4A does not operate through between terminals. The 4A and 4B run through the same intervals, as the route splits between Arlington Forest and Rosslyn station.

The Pershing Drive–Arlington Boulevard Line was introduced in 1926, as the route was part of the Washington Virginia & Maryland Coach Company.[1] It was later operated by WMATA in 1973, when it acquired all routes from the WV&M. Since 1973, the Pershing Drive–Arlington Boulevard Line consists of all 4 line. The 4 line provides reliable service within Fairfax and Arlington counties to connect from neighborhoods, to marketplaces, to landmarks, and to business. The Pershing Drive–Arlington Boulevard Line is a unique line, in which it retains its original name, without changing its name during service changes, despite that it ran under the Arlington Boulevard Line when it was operated by the WV&M.

After WMATA acquired the 4 line in 1973, the 4 line have its former terminus throughout the years. The 4A once operated between Rosslyn Metro and Culmore vía Arlington Boulevard. The 4B operated once to Jefferson Village (now West Falls Church), a neighborhood in Fairfax County.[2] There was also routes 4E, 4H, and 4S which is part of the line alongside with routes 4A and 4B.[3] Routes 4E, 4H, and 4S all operates up to Rosslyn station alongside with the 4A and 4B, however, the 4E starts from the neighborhood of Arlington Forest, the 4H from Seven Corners, and the 4S from Sleepy Hollow Road in Fairfax County. The 4A operates during weekdays, while the 4B ran daily, the 4E runs on a one way route during morning rush hours, the 4H runs during late night and Saturdays, and the 4S runs during rush hours, morning peak to Rosslyn and afternoon peak to the neighborhood of Sleepy Hollow.