Improvements to the Milton line were proposed in
The Big Move, Ontario's regional transportation plan (RTP) published in 2008. As part of the plan, there would be two-way, all-day rail service to Milton, slated to be in place within 15 years of the announcement (by 2023). In 2013,
The Big Move was updated and Milton line enhancements were shifted to a 16-to-25-year planning horizon. The update also cut back the western terminus of two-way service to
Meadowvale GO Station in Mississauga. Improvements to the line would therefore not service Lisgar station in Mississauga, nor Milton's station, service which had been promised by the provincial Liberals Halton candidate during the 2011 election. As a result of this deferral to a longer-term timeline for the improvements, Milton town councillor Rick DiLorenzo has referred to the Milton line as the "orphan" of Metrolinx. An objective of the update to
The Big Move was to align
The Big Move with
GO 2020, a transportation plan published by GO Transit in 2008.
GO 2020 called for all-day 30-minute service to Meadowvale with bus connections to Milton. It also proposed 15-minutes service to Meadowvale in peak periods with express service during high-demand periods. Reports cited "significant infrastructure and operational challenges that mean it will not be possible to deliver two-way, all-day service all the way to Milton in the 15-year time horizon. Additional tracks and potentially numerous grade separations are necessary are a prerequisite to the expansion of service to Milton. The construction is especially challenging through built-up areas. This rail corridor is largely owned by CPR, a private third party operating freight rail. Their approval is required for any service and infrastructure expansion. Two-way, all-day service can be delivered to Meadowvale in the 15-year timeframe, but the full extension to Milton can only be delivered over the 25-year horizon." On August 10, 2021, the federal government indicated a willingness to partially fund an upgrade to the Milton line to handle all-day, two-way train service, but gave no timeline or a specific funding amount. Such an upgrade would cost about $1 billion. Before 2020, the line carried 30,000 passengers per day; however, freight traffic was a constraint against expansion of commuter service. In February 2024, the Ontario government announced a plan to build dedicated tracks in the Milton corridor to enable two-way all-day service. The unfunded plan was estimated to cost more than $6 billion.
Extension to Waterloo Region The
Regional Municipality of Waterloo funded a study indicating that a $110 million extension of the Milton line could bring trains to
Cambridge by 2012, with possible stations at Guelph Line in
Campbellville, Highway 6 in
Puslinch, and at Franklin Boulevard (a
park and ride) and Water Street (downtown with transit connections) in Cambridge. However, the plans didn't come to fruition when an environmental assessment became a victim of budget cuts. GO Transit expects expansion of train service to Cambridge to happen in the 15 to 25 year time frame, after passenger capacity upgrades at Milton to relieve current train overcrowding. ==Station list==