Since the 1940s that the City of Toronto had considered widening Spadina Avenue. But it was only in 1953 that a team of engineers designed plans for the Spadina Expressway, along with six other new highways and extensions in and around the city. Their original plan was for the Spadina Expressway to connect Highway 401 and the Gardiner Expressway by running south from Downsview Airport, parallel to Bathurst Street; turning east between Eglinton Avenue and St. Clair Avenue, until meeting Spadina Road at Davenport Road; then turning south again towards the Gardiner. The expressway portion was to end between Harbord and College streets, in the Annex neighbourhood, then continue south as a major arterial road. The section north of Eglinton was to be depressed and contain a rapid transit line in the middle. Metro Toronto Planning Board approved the project in October 1961, but the cloverleaf interchange near the Yorkdale Shopping Centre, at the expressway’s northern start, was approved in July 1959. Both the T. Eaton’s Co. and Metro’s Chair Fred Gardiner leaned on each other to justify their respective projects, as the mall became a major reason why the controversial expressway was approved and its northern stretch was built.

Shopping malls were a postwar urban innovation driven by North America’s sprawling suburbs and their dependence on the automobile. In metropolitan Toronto, the number of car-oriented shopping centres grew from a handful in the early 1950s to over 200 by the mid-1960s. The largest and most successful of these was Yorkdale Mall. In the mid-1950s, the T. Eaton’s Co. bought the 40-hectares area on the southeast side of Highway 401 and Dufferin Street, where it planned to build a department store targeting the fast expanding suburbs of metropolitan Toronto, in a 28-minute drive radius. In 1958, Eaton’s invited its rival Simpson’s to buy an adjacent 8 hectares and publicly announced its development plans. Together with Dominion, the three large retailers formed the anchor stores of the 1.2 million sq. ft. Yorkdale Mall, surrounded by a 54-acre parking lot. The following year, the Spadina Expressway cloverleaf interchange was approved by Metro Council, which confirmed the future mall’s privileged location for suburban shoppers.

Metro Council, then chaired by William Allen, approved a revised version of the project in August 1963. Construction began shortly after that. The northern section, connecting Wilson Heights to Lawrence Avenue – today known as Allen Road – opened on October 21, 1966. Meanwhile, opposition to the project grew, including from Toronto City Council, which privileged public transit over expressways. This prompted Metro Council to pause its construction in September 1969. The following month, a group of young urban activists and academics founded the Stop Spadina Save Our City Coordinating Committee, moved by environmental, heritage, and local community preservation concerns. Their successful campaign convinced Premier Bill Davis to cancel the project on June 3, 1971. Gerry Gallagher of the Laborers’ Local 183 opposed this cancellation citing the many jobs that its union members would lose at a time of growing unemployment. After this, Gallagher became a vocal opponent of “anti-development” reform politicians like the future Mayors John Sewell and David Crombie.