Government of Ontario Transit (later shortened to "GO Transit") started as a three-year long experiment 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. GO Train service ran throughout the day from Oakville to Pickering with limited rush hour train service to Hamilton. The experiment proved to be extremely popular; GO Transit carried its first million riders during its first four months, and averaged 15,000 per day soon after. This line, now divided as the Lakeshore East and Lakeshore West lines, is the keystone corridor of GO Transit. Expansion of rail service continued in the 1970s and 1980s, aimed at developing ridership in with the introduction of the Georgetown (now Kitchener) line in 1974 and the Richmond Hill line in 1978. The Milton GO Train line opened in 1981, followed by the Bradford (now Barrie) and Stouffville lines a year later, establishing GO Transit's present-day service of seven rail corridors.