Canadian Pacific Kansas City's Galt Subdivision is CPKC's 114.6 mile long section of its Montréal-Detroit freight corridor.

The rest of the line plays host to mixed freight and intermodal traffic, from Toronto to termini like Detroit, and Chicago.

Passenger rail service would be partly restored halfway through the line through the introduction of GO Transit operations in 1981 westward only as far as the Town of Milton.

The stations along the line are (from Milton east to Union): More recently, GO Transit has stopped deadheading their trains to Guelph Junction for overnight and weekend storage - they have built a yard just west of 5th line in Milton, with a connecting siding directly from the GO station.

They do not run the full length of the line, as the portion that ran south-east to Union Station was sold to Metrolinx/GO transit.