There are a number of freeways that serve both the city proper and the Greater Toronto Area. Bisecting the city from west to east across its inner suburbs, Highway 401 (or simply, "the 401") acts as a bypass of the downtown core, and is both the busiest and widest highway in Canada. At its intersection with Highway 400, where it spans 22 lanes, it sees over 400,000 vehicles on an average day.
At the western edge of the city, the 401 meets Highway 427, an important north-south artery between Toronto Pearson International Airport and the Gardiner Expressway. It mainly serves the airport and the western suburbs outside the city of Toronto. In the same area, the short length of Highway 409 connects the airport directly to the traffic flow of the 401. Moving east, the 401 then intersects Highway 400, which leads north to Barrie, the recreational areas of Ontario's "Cottage Country" and beyond, to the northern reaches of the province. East of the 400, the 401 meets Allen Road, and then the Don Valley Parkway/Highway 404, before continuing eastwards out of Toronto into the suburbs of Pickering, Ajax, Whitby, and Oshawa.
Forming part of Toronto's municipal expressway system, the Don Valley Parkway (or colloquially, the DVP, or sarcastically, the 'Don Valley Parking Lot' because of its constant congestion due to the fact it is the only north-south highway which services the city; resulting in comparable congestion on the major north-south roads within the DVP's immediate vicinity) links downtown to the old inner suburbs immediately to the north and east. Beyond the 401, this route is known as Highway 404, and connects the more distant outer suburbs of Markham, Richmond Hill, Aurora, and Newmarket to the city.
Allen Road forms the completed stretch of the proposed Spadina Expressway that would have run along the Cedarvale Ravine and across The Annex.
The Gardiner Expressway (or colloquially, "the Gardiner") roughly follows the northern shore of Lake Ontario, and connects the western suburbs to the downtown core. West of Highway 427, the Gardiner becomes Queen Elizabeth Way (often called the QEW, or simply "The Q.E."), which heads towards Hamilton, Niagara, and Fort Erie (bordering New York State in the vicinity of Buffalo).
Highway 407 ETR is not located within Toronto proper, but is a major highway in the Greater Toronto Area that acts as a secondary bypass around the northern end of the city, stretching from Burlington in the west to Pickering in the east. It is an electronic toll road with no physical toll booths, instead depending on automatic recognition of vehicle plates or electronic toll collection.