400-series highways in the context of "Northern Ontario"

A controlled-access highway is a type of highway that has been designed for high-speed vehicular traffic, with all traffic flow—ingress and egress—regulated. Common English terms are freeway, motorway, and expressway. Other similar terms include throughway or thruway and parkway. Some of these may be limited-access highways, although this term can also refer to a class of highways with somewhat less isolation from other traffic.

In countries following the Vienna convention, the motorway qualification implies that walking and parking are forbidden.

King's Highway 401, commonly referred to as Highway 401 and also known by its official name as the Macdonald–Cartier Freeway or colloquially referred to as the four-oh-one, is a 400-series highway in the Canadian province of Ontario. It is an 828-kilometre-long (514 mi) freeway, travelling from Windsor in the west to the Ontario–Quebec border in the east (west of Montreal). The part of Highway 401 that passes through Toronto is North America's busiest highway, and one of the widest in Canada. Together with Autoroute 20 (A-20), it forms the road transportation backbone of the Quebec City–Windsor Corridor, along which over half of Canada's population resides. It is also a Core Route in Canada's National Highway System. The route is maintained by the Ministry of Transportation of Ontario (MTO) and patrolled by the Ontario Provincial Police (OPP). The speed limit is 100 km/h (62 mph) throughout the majority of its length, with the remaining exceptions being the posted 80-kilometre-per-hour (50 mph) limit westbound in Windsor, in most construction zones, and the 110-kilometre-per-hour (68 mph) speed limit on the 40-kilometre (25 mi) stretch between Windsor and Tilbury that was raised on April 22, 2022, the 7-kilometre (4.3 mi) extension east of the aforementioned, the 35-kilometre (22 mi) stretch between Highway 35 / 115 and Cobourg, the 44-kilometre (27 mi) stretch between Colborne and Belleville, the 66-kilometre (41 mi) stretch between Belleville and Kingston, and the 107-kilometre (66 mi) stretch between Highway 16 and the east end of the freeway that were raised on July 12, 2024.

By the end of 1952, three individual highways were numbered Highway 401: the partially completed Toronto Bypass between Weston Road and Highway 11 (Yonge Street); Highway 2A between West Hill and Newcastle; and the Scenic Highway between Gananoque and Brockville, now known as the "Thousand Islands Parkway". These three sections of highway were 11.8, 54.7, and 41.2 kilometres (7.3, 34.0, and 25.6 mi), respectively. In 1964, the route became fully navigable from Windsor to the Ontario–Quebec border. In January 1965, it was given a second designation, the Macdonald–Cartier Freeway, in honour of two Fathers of Confederation. At the end of 1968, the Gananoque–Brockville section was bypassed and the final intersection grade-separated near Kingston, making Highway 401 a freeway for its entire 817.9-kilometre (508.2 mi) length. In August 2007, a portion of Highway 401 between Trenton and Toronto has been designated as the Highway of Heroes, as the route is travelled by funeral convoys for fallen Canadian Forces personnel from CFB Trenton to the coroner's office in Toronto.

King's Highway 407, commonly referred to as Highway 407 and colloquially as the "four-oh-seven", is a 400-series highway in the Canadian province of Ontario. Comprising a tolled privately leased segment and a publicly owned segment, the route spans the entire Greater Toronto Area (GTA) around the city of Toronto, travelling through the suburbs of Burlington, Oakville, Mississauga, Brampton, Vaughan, Markham, Pickering, Whitby, and Oshawa before ending in Clarington, north of Orono and Newcastle. At 151.4 kilometres (94.1 mi) long, it is the fourth-longest expressway in Ontario's 400-series network, after Highways 417, 400, and 401. The tolled segment between Burlington and Brougham in Pickering is leased to and operated by the 407 ETR Concession Company Limited and is officially known as the 407 Express Toll Route (407 ETR). It begins at the Freeman Interchange between the Queen Elizabeth Way (QEW) and Highway 403 in Burlington; the highway travels 108.0 km (67.1 mi) across the urban GTA to Brock Road in Pickering. East of Brock Road, the freeway continues east as Highway 407 (referred to as Highway 407 East during development to distinguish it from 407 ETR), a route operated by the provincial government and formerly tolled, for 43.4 km (27.0 mi) to Highway 35/115 in Clarington. The route interchanges with nine freeways in Ontario: the QEW, Highway 403, Highway 401, Highway 410, Highway 427, Highway 400, Highway 404, Highway 412, and Highway 418. 407 ETR is an electronically operated toll highway; there are no toll booths along the route. Distances are calculated automatically using transponders or automatic number-plate recognition, which are scanned at entrance and exit portals.

Highway 407 was planned in the late 1950s as a freeway bypassing Toronto's segment of Highway 401, the busiest highway in North America. However, construction did not begin until 1987. During the early 1990s, the provincial government proposed tolling the highway to alleviate a revenue shortfall. The central sections of Highway 407 opened in 1997, and the remaining sections were built quickly over the following four years, with the final segment opening in mid-2001. Despite being included in the 400-series network, the Highway 407 ETR section is not considered part of the provincial highway network as it is now privately operated. The segment is operated privately under a 99-year lease agreement signed with the Conservative provincial government, which was sold in 1999 for about C$3.1 billion to a consortium of Canadian and Spanish investors operating under the name 407 International Inc. The privatization of the Highway 407 ETR section has been the source of significant criticism, especially regarding increases in tolls, plate denial, and false charges. In addition, the safety of segments built after the sale of the freeway has been called into question.

The Greater Toronto and Hamilton Area (GTHA) is an urban conurbation that is composed of some of the largest cities and metropolitan areas by population in the Canadian province of Ontario. The GTHA consists of the Greater Toronto Area (GTA) and the City of Hamilton. Unlike the Golden Horseshoe, which covers a larger area, the GTHA specifically refers to the urban conurbation of these regions. Despite not being in the conurbation's name, it also includes the City of Oshawa and its sub-metropolitan area. The GTA is Canada's most populous metropolitan area that includes the core City of Toronto and the regional municipalities of Halton, Peel, York, and Durham (which contains Oshawa). The GTHA forms the core of a larger urban agglomeration known as the Golden Horseshoe.

Beginning in the late-2000s, the term "Greater Toronto and Hamilton Area" was introduced by a few public bodies to refer to the GTA and the city of Hamilton as a single entity. The population of the combined area was 7,281,694 people as of the 2021 census and was estimated to be 8,302,789 as of 2024. The main series of roadways that connects all the areas together (going from Durham to Hamilton) includes highways 401, 427, 403, and the Queen Elizabeth Way. The GTHA has regional public transport served by GO Transit and local service by multiple agencies, which mostly use the Presto card as fare payment.