The route serves the northeastern suburbs of Philadelphia, Pennsylvania with service in Bucks County along the Delaware River to Trenton, New Jersey.

The line's termini, 30th Street and Trenton Transit Center, have long been among the busiest Amtrak stations in the country.

[citation needed] SEPTA activated positive train control on the Trenton Line on May 1, 2017.

Many stations outside the city limits have a ticket office as well, however they have shorter hours (most outside the city limits are closed on weekends) and fewer amenities than the ticket offices inside the stations within Philadelphia.

[6][4] Between FY 2013–FY 2019 yearly ridership on the Trenton Line ranged from 3.1–3.6 million before collapsing during the COVID-19 pandemic.