King's Highway 427 (pronounced "four twenty-seven"), also known as Highway 427 and colloquially as the 427, is a 400-series highway in the Canadian province of Ontario that runs from the Queen Elizabeth Way (QEW) and Gardiner Expressway in Toronto to Major Mackenzie Drive (York Regional Road25) in Vaughan, near the hydro towers. It is Ontario's second busiest freeway by volume and the third busiest in North America, after Highway 401 in Ontario and Interstate 405 in California. Like Highway401, a portion of the route is divided into a collector–express system with twelve to fourteen continuous lanes. Notable about Highway427 are its several multi-level interchanges; the junctions with the QEW/Gardiner Expressway and Highway401 are two of the largest interchanges in Toronto (and Ontario) and were constructed between 1967 and 1971, while the interchanges with Highway 409 (Toronto) and Highway 407 (Vaughan) were completed in 1992 and 1995, respectively.
Highway427 is one of two complete north-south freeways in Toronto, the only other one being Highway404/Don Valley Parkway (DVP) serving North York and Scarborough. Highway427 serves as a major traffic route for the western portion of Toronto (Etobicoke), the northeastern portion of Mississauga (Malton), the southeastern portion of Brampton (Claireville), and the western portion of Vaughan (Woodbridge). The section of Highway427 between Highway401 and Dundas Street (Highway 5) is a heavily traversed transit corridor; the stretch between Burnhamthorpe Road and Rathburn Road saw an average of over 400,000 vehicles and over 5,000 buses per day in 2016, including express buses from GO Transit, MiWay, and the Toronto Transit Commission (TTC). The freeway is also the main feeder to Toronto Pearson International Airport from the north and south, as a considerable amount of traffic from Highway401 (eastbound), the QEW/Gardiner Expressway, and Highway407 make use of the route for airport access.
First designated in 1972, Highway427 assumed the recently completed, 12-lane, collector-express freeway of Highway 27, as well as a short freeway north of Highway401 known as the Airport Expressway. Both routes were upgraded throughout the 1950s and 1960s, eventually becoming intertwined into the present configuration in 1972. The freeway was extended north from Pearson Airport to Highway 7 over the following twenty years. Construction of an extension north to York Regional Road 25 (Major Mackenzie Drive) began in May 2017 and was opened on September18, 2021.
The speed limit is . The route is patrolled by the Ontario Provincial Police (OPP) and maintained by the Ministry of Transportation of Ontario (MTO).
Route description
Highway 427 is the second-busiest freeway in Canada with an average of 300,000 vehicles that use it between the QEW and Highway401 per day. The section between Burnhamthorpe Road and Rathburn Road (south of Highway401) has an annual average daily traffic (AADT) count of 353,100 vehicles. The route was long from 1991 until 2021, when the latest extension increases its length to approximately .
At its southern terminus, the highway begins at Coules Court, where it continues as Brown's Line, once the southernmost stretch of Highway27. Alderwood Plaza, located on the east side of the route, has a parking lot which provides access to the highway; this is the only at-grade access along the length of the route. The four-lane arterial road splits into a divided highway, then descends below Evans Avenue, where a northbound exit ramp to the latter allows indirect access to the Hamilton-bound QEW at the intersection with The West Mall (TWM), plus there are also connecting ramps to the highway north of Evans Avenue. The highway then weaves through a complicated, semi-directional T interchange, providing northbound access to Evans Avenue and the Gardiner Expressway, and southbound access to The Queensway, the QEW/Gardiner Expressway, and Evans Avenue. North of that massive interchange, the lanes from Brown's Line diverge and form the collector lanes of a collector-express system. Flyover ramps to and from the QEW/Gardiner pass over the southbound lanes and converge to form the express lanes. This collector-express system serves to divide local traffic from freeway-to-freeway traffic; the express lanes provide access between the QEW/Gardiner Expressway and Highway401, while the collector lanes provide local access between those interchanges.
After crossing Canadian Pacific Railway (CPR) tracks, the highway interchanges with Dundas Street (formerly Highway 5). A set of criss-crossing ramps provide access between the collector and express lanes north of this point, referred to as "The Basketweave", with the northbound express-to-collector transfer also having an offramp to The East Mall (TEM) and Dundas Street. North of Dundas, Highway427 has a northbound right-in/right-out (RIRO) interchange with Gibbs Road, the first of several that provide collector lane access to minor streets that mostly connect to The East Mall and The West Mall, which run parallel with the collector-express section of the highway. The highway passes beneath Bloor Street, then a full Parclo A4 interchange is provided shortly after with Burnhamthorpe Road, southwest of Burnhamthorpe Collegiate Institute. Across from the school, another RIRO provides access from the southbound lanes to Holiday Drive and The West Mall (which terminates). Following the off-ramp, to the north, is a half-cloverleaf interchange with Rathburn Road, which provides access from the northbound lanes and to the southbound lanes.
Transfers provide a second and final opportunity to cross between the express and collector lanes (or vice versa), south of the complicated, Highway401 spaghetti interchange. A final RIRO provides southbound access to and from Eringate Drive, after which the collector lanes diverge, and the express lanes cross the southbound collectors. The collector lanes cross Eglinton Avenue at a half-cloverleaf interchange and then dives under Highway401 while transitioning into Highway27, while the express lanes interchange with Highway401 and continue the route of Highway427. The Highway 427 express lanes, along with ramps connecting to Highway 401, are constructed around the Richview Memorial Cemetery. Highway427 passes through the sprawling Highway 401 Interchange and becomes displaced approximately to the west. There are no ramps to provide access from southbound Highway427 to eastbound Highway401 (and vice versa), as this connection is handled by Highway 409.
Highway 427 crosses Renforth Drive, then curves to the east of Runways24R and 24L of Toronto Pearson International Airport. Shortly thereafter, the freeway narrows to eight lanes before it crosses Dixon Road and Airport Road (Peel Regional Road 7), between which the freeway forms the demarcation line. At the Dixon Road partial interchange, which only serves the freeway south of this junction, another ramp branches off and passes under the highway, providing access to Pearson Airport. From here to just south of Finch Avenue, the freeway follows the boundary line between Toronto and Mississauga. The freeway encounters the third multi-level junction along its length, a cloverstack with Highway409, which provides access to the airport for the freeway west of this junction. This interchange also provides the southbound movement to eastbound movement to Highway401, via a flyover ramp to Highway409, that cannot be performed at the larger interchange with Highway401 to the south. There is no movement from northbound to westbound at the interchange with Highway409, since airport access is already provided at the Dixon Road exit to the south. Highway427 continues straight north and narrows again to six lanes.
After crossing the GO Transit Kitchener Line, it passes west of Woodbine Racetrack and interchanges with Rexdale Boulevard/Derry Road and Finch Avenue (Peel Regional Roads 5 and 2). The freeway bends slightly eastward, diverging from the Toronto–Mississauga boundary to briefly run exclusively through Toronto again. It crosses the West Humber River where it drains from the Claireville Reservoir. The highway crosses Steeles Avenue and enters Vaughan, as it approaches a fourth and final sprawling interchange with Highway407 Express Toll Route, then passes beneath a hydro corridor. Highway 427 then interchanges with Highway 7 (York Regional Road 7), Langstaff Road (York Regional Road 72), and Rutherford Road (York Regional Road 73), and finally ends at a trumpet interchange with Major MacKenzie Drive(York Regional Road 25). At a trumpet interchange, the northbound exit ramp from the freeway defaults into Garnet Williams Way, a local side street.
History
QEW to Highway 401 (1953–1956)
Although Highway427 was not officially designated until 1972, several sections of freeway were already in place prior to that date. The designation was applied following the completion of the interchanges at the QEW and Highway401 as well as the expansion of the section between them into a collector-express system.
Highway27 was designated as a two-lane road travelling north from Highway 2 (Lake Shore Boulevard) towards Barrie. As Toronto grew outwards following the annexation of various municipalities, the Ontario 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 interchange 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 airport expansion, the DHO built a new four-lane freeway known as the Toronto Airport Expressway which opened on January 3, 1964. This new route ran north from Highway401 at Renforth Drive to Dixon/Airport Roads (roughly followed the same alignment as today's Highway 427) where it tied in with and downgraded into Indian Line. The Airport Expressway 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. On Highway401 the Airport Expressway interchange was located to the west on the existing interchange with Highway27.
Expansion (1963–1971) In 1963, MacNaughton announced that Highway 401 would be widened from a four-lane highway to a collector-express system, modeled 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.