The SEPTA Trenton Line operates along the portion of the Northeast Corridor between Philadelphia and Trenton, NJ. In Trenton passengers can make generally well timed connections with NJ Transit Trains to continue New York City. NJ Transit even sells rudimentary SEPTA one-way tickets to/from Trenton as either Intermediate tickets (all stops through North Philadelphia), Tunnel (travel to and from all other Regional Rail Stations), or Philadelphia 30th Street (Center City Philadelphia, also valid all the way to Temple University).
Service along the line is hourly throughout the day on both weekdays and weekends. During Weekdays most non-rush hour trains are interlined with the Chestnut Hill East Branch continuing there after stopping at Temple University. This is exactly as operations ran when the Trenton Line was combined with the Chestnut Hill East line as part of the R7 designation from the opening of the Center City tunnel in 1984 until the R-designations were dropped in 2010. A few weekday rush hour trains interline with other lines or terminate at Temple University Station.
On weekends all service is operated independently, not interlining with any other Regional Rail Lines with most trains terminating at Market East station except for the first train and last three trains of the day terminating at Temple University, and in reverse, the first three and last trains of the day originating at Temple University.
The line is entirely along a four-track section of the Northeast Corridor although the stations are generally very rudimentary, with just two stops rebuilt into modern high-level platform stations so far. Some stations even require crossing a freight track to reach regional rail trains. These tiny stations make the stops on the SEPTA line the kind that are extremely easy to miss on a high-speed Amtrak express train, with all intermediate stops bypassed along the Trenton Line except for a few Keystone trains that still stop at North Philadelphia and Cornwells Heights.