[citation needed] The corridor was opened by the Pennsylvania Railroad in 1892[1] to allow main line freight traffic to run between New York City and Harrisburg without passing through Philadelphia.

[3] A low-grade line (one with very gradual rises and descents), the Trenton Cutoff runs from Conrail Shared Assets Operations' Morrisville Yard on the Northeast Corridor to GLEN interlocking where it joins the Amtrak-owned Keystone Corridor (Philadelphia to Harrisburg Main Line).

From Ernest west to GLEN interlocking, the Trenton Cutoff is a single track in dark (unsignaled) territory.

[citation needed] Originally a two-tracked electrified rail line, the catenary wire over the tracks was dismantled by Conrail to provide greater overhead clearance for double-stack container trains.

[citation needed] The high voltage transmission lines running along the Trenton Cutoff from Norristown, where the Trenton Cutoff crosses over the abandoned Pennsylvania Railroad Schuylkill Branch, to Glenloch are part of Amtrak's 25 Hz traction power system, used to power trains on the Northeast Corridor and the Keystone Corridor.