Department of Highways (DHO) began planning for a bypass of the city, aptly named the Toronto Bypass. A significant portion of this bypass was designed to be incorporated into the Transprovincial Highway, now Highway401. The remainder was designed to follow the existing right-of-way of Highway27 between the QEW and Richview Sideroad (now Eglinton Avenue). Construction of the Toronto Bypass began near Yonge Street in 1949 (along present-day Highway401) and on the four-laning of Highway27 in 1953. The Highway27 work involved the construction of two interchanges: a three-way stack at Highway401 and a large cloverleaf at the QEW, the latter of which would become one of the worst bottlenecks in the province a decade after its completion, according to Minister of Transportation Charles MacNaughton. By September 1956, it was possible to bypass Toronto entirely on the four lane divided highway composed of Highway401 and Highway27. Highway401 was extended to the west soon after, but Highway27 remained a two-lane highway north of it. Airport Expressway (1964–1971) During the early 1960s, Toronto International Airport was expanded with the construction of the Aeroquay One terminal. To serve the expected demand of the expansion, the DHO built a new four-lane freeway north from Highway401 at Renforth Drive. This new route, which roughly followed the same route as today's Highway 427 as far as Dixon/Airport Roads where it tied in with and downgraded into Indian Line, was known as the Toronto Airport Expressway and was opened on January 3, 1964. It featured a connection with the western terminus of Richview Sideroad at the southern end of the interchange with Highway401 as well as an interchange with Renforth Drive. Expansion (1963–1971) In 1963, MacNaughton announced that Highway 401 would be widened from a four-lane highway to a collector-express system, modelled after the Dan Ryan Expressway in Chicago. Plans were soon developed to apply this model to the QEW between Highway27 and Royal York Road and to Highway27 between the QEW and Highway401, and were unveiled to Etobicoke council on October13, 1966. Design work followed and was completed by May 1967. This reconstruction once again involved the junctions with the QEW and Highway401, which were reconfigured into complicated multi-level interchanges to permit free-flow movement; construction began in September 1968. The widening of Highway27 required the demolition and rebuilding of overpasses at Bloor Street, Burnhamthorpe Road, and Rathburn Road constructed just over a decade earlier. The junction with the