The route begins at a loop around Suburban Square shopping center in Ardmore, then heads west along Montgomery Avenue. A short distance later, it turns left at Woodside Road, crossing under the Paoli/Thorndale Line near Ardmore, which also serves Amtrak's Keystone Service. After its stint on Woodside, it takes a left onto Lancaster Avenue. While Route 103 is close to the Ardmore station in this area, it doesn't have a direct connection to the station aside from a walk across the parking lot near the station at Suburban Square. From Lancaster Avenue, Route 103 is divided. Southbound buses use Rittenhouse Place, East Athens Avenue, and Cricket Avenue to County Line Road. Northbound buses from County Line Road use Ardmore Avenue to Lancaster Avenue. Shortly after the split between Lancaster Avenue and County Line Roads, Route 103 makes a turn onto a private Ardmore Busway, also known as Hathaway Lane, where it immediately encounters County Line Road station, which is little more than a shed. The private busway was originally right-of way for the trolley rails until it was paved over, which is why some of the old P&W/Red Arrow Line sheds still remain intact. The exception to this is the plexiglass bus shelter at Belmont Avenue station. Although Hathaway Lane continues to serve as a private road strictly for the Route 103 bus south of Haverford Road, there are some sections that contain parallel roads for residents and the general public. Both the busway and West Hathaway Lane go under the Norristown High Speed Line at Ardmore Junction station. Merwood Road station contains residential parallel roads on both sides of the busway. Though the Ardmore Busway ends at the intersection of Darby Road & Eagle Road in Oakmont, a "Red Arrow" bus shelter can be found after the intersection on Darby Road. The former trolley right-of-way runs west of Darby Road while the current bus route runs down Darby until making a left turn at Brookline Boulevard in Havertown. From there, the bus heads east and makes a right turn onto Earlington Road as it runs south again through Penfield. When Earlington Road ends at Township Line Road the bus turns left then heads up to 77th Street. It then turns right onto 77th Street, entering the Philadelphia city limits. Route 103 then turns left onto Woodbine Avenue, then a right onto 75th Street. It then travels down that street for about 4 blocks, then buses merge into Lansdowne Avenue before making a quick left onto Cardington Road/Victory Avenue. Buses then make a left onto a private SEPTA access road to terminate at the north terminal of 69th Street Transportation Center.
History
Route 103 buses took over SEPTA Route 105 routing from 77th Street & City Avenue to 69th Street Transportation Center in the early 2000s. Before then, the route merged West Chester Pike where it joined its counterpart Route 104, another Red Arrow Bus Lines converted from trolleys in 1954. The two routes together. A mural of a trolley station was painted on a building on the corner where this right-of-way used to exist. From this point both the Routes 103 and 104 buses continued eastward along West Chester Pike until reaching the west terminal at 69th Street. Today the North Terminal is also served by five other SEPTA bus routes;. The west terminal continues to serve trolleys today; Routes 101 and 102, the Media/Sharon Hill Line, both former trolleys of the Philadelphia Suburban Transportation Company.
