[3] The GO Transit rail fleet consists of 90 MPI MP40 locomotives and 979 Bombardier BiLevel Coaches.

GO Transit started on May 23, 1967, running single-deck trains powered by diesel locomotives in push-pull configuration on a single rail line along Lake Ontario's shoreline.

[5][6] When GO trains began operation, they ran on tracks mostly owned the two major freight railways of Canada: Canadian National (CN) and CPKC.

[7] in 1988, a small but significant milestone in network growth occurred when it expanded its Lakeshore East line on new track it built by itself.

A 20km extension of the Lakeshore East line to Bowmanville was announced by then-premier Kathleen Wynne in 2016.

[19] The Milton line is owned and operated by Canadian Pacific Kansas City which has restricted the number of passenger trains, only allowing for one-way service.

Hydrogen fuel cells were studied as an alternative to rail electrification but ultimately were deemed unfeasible.

[22] In 2022, the Ontario government under premier Doug Ford began the first phase of electrification, with plans to electrify 600 kilometres of track and an estimated finish date of 2032.

[23] GO Transit rail service to Bolton was first proposed by the Ontario government under the MoveOntario 2020 plan in June 2007.

Four different service alternatives were assessed to determine the best method to carry passengers into Toronto from the Mactier subdivision, and the preferred option was to direct trains east-west along CN's Halton subdivision, and north-south again along GO Transit's existing Barrie line.

Metrolinx determined that the projected ridership did not justify the costs, and downgraded the Bolton line from the 15- to the 25-year plan on February 14, 2013, when amendments were made to The Big Move.

[28] However, the Havelock line was moved to the 25-year plan on February 14, 2013, because of "very modest ridership potential and significant infrastructure and operational challenges related to the Agincourt rail yards.

The potential to provide commuter rail service to Peterborough was noted by GO Transit in its 2020 strategic plan, and was also included in The Big Move.

[28][32] Metrolinx completed a study for bringing commuter rail service to Peterborough in February 2010.

Once reaching Toronto, three different routes were explored through the east end, to deal with the same "significant infrastructure and operational challenges related to the Agincourt rail yards" that complicate GO's Havelock line.

Reports have forecasted a ridership of over 500,000 by 2041, and would cut travel time between Cambridge and Union Station to 87 minutes.

Another guard-like staff member, the Customer Service Ambassador (CSA), is located in the accessibility coach, which is the fifth car from the locomotive.

The CSA is responsible for opening and closing the train doors, making announcements over the PA system, and acts as the first responder in case of an emergency on board.

When a train arrives at a station, the CSA puts a small accessibility bridge across the gap between the platform and the doorway.

This is to allow passengers with mobility devices such as wheelchairs, walkers, or strollers to board and exit the train.

GO Transit inspects train air conditioning more frequently during summer, as A/C systems have to work harder on hot days.

They are 3000-horsepower diesel-electric locomotives capable of travelling up to 134 kilometers an hour, and can accelerate a ten-car train from 0 to 100 km/h in about 75 seconds.

The F59PH was also the first series of locomotives used by GO Transit that feature dynamic braking, the effectiveness of which was greatly increased to as low as 8 km/h.

[53] In 2005, GO Transit contracted with MotivePower to build 27 MP40PH-3C units in order to expand its fleet and replace the existing F59PH locomotives which had been in service for almost 20 years.

Another ten MP40PH-3C locomotives were purchased later and were delivered in 2013 and 2014 when GO Transit found that additional equipment was required to expand rail service.

It includes two progressive maintenance bays, repair shops for 11 coaches and 12 locomotives, two washing stations and storage tracks for 13 trains.

[56] The facility was constructed to handle service expansions, which include the GO Transit Regional Express Rail program.

[57] Metrolinx is planning a new storage facility along the Richmond Hill GO Line south of Oriole GO Station near York Mills Road.

In December 2018, GO Transit banned CSA Gordon "Gord" Plumridge from singing Christmas carols over the PA system on the train after a complaint from a passenger.

"[68] She stated that a compromise was made between Plumridge and Bombardier, the company who was contracted to provide services to GO Transit.