Route 6 begins at the Olney Transportation Center, a core station of the Broad Street Line, principally traversing Ogontz Avenue in Philadelphia, crossing the City Line at Cheltenham Avenue, and then proceeding on private right-of-way down the middle of Limekiln Pike before running as a streetcar line on Keswick Avenue in Glenside, and then mostly side-of-the-road private right-of-way until reaching Willow Grove Park.

Route 6 was cut back to a loop and terminus at Ogontz & Cheltenham Avenues at the City Line.

As one of the newer trolleys to be adopted by SEPTA, the Route 6 trolley was established by the Philadelphia Rapid Transit Company (PRT) in 1907, although some sources[1] claim it was established in 1924, as the Glenside Line between the Willow Grove Depot and the City Line and Ogontz Avenue via Limekiln Pike.

Despite public criticism by community and transit advocates, SEPTA voted to close the Route 6 trolley line on October 23, 1985.

Service along Keswick Avenue and Edge Hill Road, the original trolley route, was eliminated.