The line is currently used by the East Penn Railroad, serving Quakertown's industrial complexes and distribution centers.

With 6,884 daily riders every weekday in FY 2022, it is the second busiest line in SEPTA's Regional Rail network.

Equipment consisted of dark green painted electric multiple unit cars built at the Reading's own shops.

Some of the cars were rebuilt during the 1960s receiving air conditioning, refreshed interior and a new blue paint scheme resulting in their being referred to as "Blueliners".

Today, the line uses the Silverliner family of EMU cars which operate throughout SEPTA's Regional Rail system.

[3] Service to Bethlehem and the Lehigh Valley languished due to the post-World War II surge of the automobile as well as the opening of the Pennsylvania Turnpike Northeast Extension in 1957.

[3] Trackage north of Quakertown was dismantled after the railbed was leased for use as the interim Saucon Rail Trail.

Lansdale and Doylestown trains operated through the city center to the Paoli Line on the ex-Pennsylvania side of the system.

[11] On August 29, 2011, SEPTA adjusted the midday service pattern to encourage ridership at Colmar station, which had available parking capacity immediately adjacent to Pennsylvania Route 309.

[12][13] On December 18, 2011, SEPTA eliminated weekend service at Link Belt and New Britain due to low ridership.