Editing Barrie line (section)

===Pre-2012 peak service expansion===
On September 8, 1998, GO Transit added a second daily round trip to the line.{{sfn|Garcia|Bow}} In the early 2000s, GO Transit opened three new stations on the line: Rutherford on January 7, 2001;{{sfn|Garcia|Bow}} [[York University]] on September 6, 2002;{{sfn|Ministry of Transportation|2002}} and East Gwillimbury on November 1, 2004.{{sfn|Canada Newswire|2004}} By the end of 2005, the number of daily trains on the line had doubled again to four in each direction.{{sfn|GO Transit|2005}}

In 2006, GO Transit built a bridge at the Snider diamond,{{sfn|GO Transit|2006}} which is the junction between the Barrie Line and [[Canadian National Railway|Canadian National]]'s primary east–west freight line, the [[CN York Subdivision|York Subdivision]]. Since CN controlled both corridors, the passage of passenger trains over the diamond was often delayed by freight trains passing through the intersection. Constructing the bridge and associated trackage resulted in a [[grade separation]] of the two lines, eliminating such delays. Construction of the bridge began in February 2006, and the bridge was opened in December 2006. The entire project was completed in June 2007.{{sfn|GO Transit|2007}}

On December 17, 2007, the Bradford Line was extended to the new Barrie South GO Station and was renamed the "Barrie Line".{{sfn|GO Transit: New stations}}  Construction had begun on February 2, 2007, to construct the new Barrie South station, a new layover facility and new tracks, signals and crossings along the existing {{convert|20|km|mi|0}} railway corridor. The project cost $25 million, funded by two thirds by the federal and provincial governments, and one third by the City of Barrie.{{sfn|City of Barrie|2007}}

On December 15, 2009, Metrolinx purchased the portion of the [[CN Newmarket Subdivision|Newmarket Subdivision]] within the City of Toronto from CN for $68 million. The Barrie line trackage, from Union Station to Barrie, is now fully owned by Metrolinx. As part of the agreement, the Canadian National Railway continues to serve five freight customers located on the Newmarket subdivision between Highway 401 and the CN York Subdivision.

On January 30, 2012, the Barrie line was extended north to the newly constructed [[Allandale Waterfront GO Station]].{{sfn|Mackenzie|2012}}