Following the recommendations of the TTC, the Municipality of Metropolitan Toronto authorized plans to be created for the extension of the Yonge Subway line. The accepted plan for the subway extension would see the subway run north from Union Station to Bloor Street underneath University Avenue and west along Bloor Street, and east along Danforth Avenue.
The University Subway line would grant more straightforward access to the Ontario Legislature and hospitals and alleviate strain on the popular Yonge Subway line. The Bloor-Danforth Subway was proposed to ease the overcrowding on the Bloor Streetcar and address community growth and development changes along this east-west route.
The official ground-breaking for the University Subway line was on November 16, 1959. The two-mile route officially opened on February 28, 1963.
Construction on the Bloor-Danforth Subway line began in June 1962. The original route of the Bloor-Danforth line was to run between Keele Station and Woodbine Station. This stretch opened on February 26, 1966. Construction on the extension to the Bloor-Danforth Subway line began in 1965. These extensions to Warden Station in the east and Islington Station in the west opened on May 11, 1968. The final extensions, to Kipling and Kennedy, opened on November 22, 1980.
With the opening of the University Subway line, the TTC decided to make some radical changes to its bus routes. They adopted a grid-system and set about to create and expand its bus service. The system they adopted would see bus service rerouted to accommodate the opening of the University Subway line and to prepare for the opening of the Bloor-Danforth Subway line. This new grid system would allow for services to be better routed to the suburban areas of Metropolitan Toronto.