[2] Both lines utilize portions of the Northeast Corridor, with trains terminating at Union Station in New Haven.

This service is supplemented by eight additional roundtrips run by the Amtrak Hartford Line, which operates along the same route.

When service initially started along the line on May 29, 1990, CT Rail commuter trains were intended to be a temporary measure in order to reduce congestion along Interstate 95 during a highway construction project.

CT Rail uses the following rolling stock for its commuter rail operations: All Electric Multiple Unit cars are used on the electrified Shore Line East running on Amtrak's Northeast Corridor while locomotive hauled trains with passenger coaches are used on Amtrak's non-electrified Hartford Line.

In August 2023, CTDOT approved a $315 million contract with Alstom for 60 single-level Adessia passenger cars.