Ontario Highway 427 - Route Description

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 Highway 401 per day. The section between Burnhamthorpe Road and Rathburn Road has an Annual Average Daily Traffic (AADT) count of 353,100. The route is 19.9 km (12.4 mi) long.

At its southern end, the route begins at Coules Court, where Brown's Line becomes Highway 427. 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 road splits into a divided highway and descends below Evans Avenue. It weaves through the first of two complicated interchanges, providing northbound access to Evans Avenue and the Gardiner Expressway, and southbound access to The Queensway, QEW, Gardiner Expressway and Evans Avenue. North of the interchange, the lanes from Brown's Line diverge. Ramps to and from the QEW and Gardiner Expressway pass over the southbound lanes and converge to form the express lanes of a collector-express system, while the remainder form the collector lanes. This system serves to divide local traffic from freeway-to-freeway traffic; the express lanes provide access between the QEW / Gardiner Expressway and Highway 401, while the collector lanes provide local access between those interchanges.

After crossing Canadian Pacific Railway (CPR) tracks, the freeway interchanges with Dundas Street. A set of criss-crossing ramps provide access between the collector and express lanes north of here, referred to as The Basketweave. The highway passes beneath Bloor Street West but does not provide direct access. Instead, it provides ramps to parallel arterial roads; The East Mall and The West Mall run parallel with the freeway from Evans Avenue to Rathburn Road. A full interchange is provided shortly after with Burnhamthorpe Road, southwest of Burnhamthorpe Collegiate Institute. Across from the college, an offramp provides access from the southbound lanes to Holiday Drive and The West Mall. Following the offramp, to the north, is a partial 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 from express to collector lanes, or vice versa, south of a complicated 1.56 square kilometres (0.60 sq mi) interchange. A final set of ramps along the collector-express system provides access to and from the southbound lanes and Eringate Drive, after which the collectors diverge, and the express lanes cross the southbound collectors. The collector lanes provide access to and from Eglinton Avenue then transition into Highway 27, while the express lanes interchange with Highway 401 and continue north. Highway 427 pushes through the sprawling interchange and becomes displaced approximately 1 km (0.62 mi) to the west. Despite its size, there is no ramp to provide access from southbound Highway 427 to eastbound Highway 401. The freeway crosses Renforth Drive and then curves to the east of Runway 24R and 24L of Pearson Airport. Shortly thereafter, it crosses and interchanges with Dixon Road and Airport Road, between which it forms the demarcation line. Several ramps diverge at this point to provide access to Pearson Airport, and the freeway narrows to eight lanes.

From here to Finch Avenue, the freeway follows the boundary line between Toronto and Mississauga. It encounters the third multi-level junction along its length, with Highway 409, which provides access to the airport as well as the southbound to eastbound movement that cannot be performed at the interchange with Highway 401 to the south. Highway 427 continues straight north and narrows again to six lanes. After crossing the Georgetown GO line, it passes west of Woodbine Racetrack and beneath Rexdale Boulevard, Morning Star Drive, and Finch Avenue West; the first and last feature interchanges. The freeway bends slightly eastward and crosses the Humber River as it drains from Claireville Reservoir. The highway bends slightly northeast as it crosses the Humber River and no longer serves as the boundary between Mississauga and Toronto. Approaching the fourth and final sprawling interchange, it crosses Steeles Avenue and enters Vaughan. It passes beneath Highway 407 and crosses through an undeveloped area before terminating at its final interchange with Highway 7. The mainline continues north as a four lane arterial road to Zenway Boulevard and is designated as York Regional Road 99.