Quebec City–Windsor Corridor

During the French colonization, this area of New France was named Canada and was a single administrative unit under the governor-general (with regional deputy governors in some cities). However, only the eastern third of the corridor, from Quebec City to Montreal, was heavily settled. The major cross-country route used by voyageurs in the fur trade continued west from Montreal through the Canadian Shield along the Ottawa Valley to Lake Nipissing and Georgian Bay, passing far to the north of what would later become the Ontario part of the corridor. The lack of good farmland made that route unsuitable for settlement, however, and the frequent portages made transportation in boats larger than canoes difficult.

When the English-speaking United Empire Loyalists arrived in Canada after the American Revolution, they naturally settled along the narrow strip north of the St. Lawrence River and lower Great Lakes, where good farm land was available and larger boats could be used for transportation, and these people formed the English-speaking nucleus of what would later be Ontario (by contrast, many of the Ontario towns along the old fur-trading and logging route to the north, through the Ottawa Valley and westward, still have significant French-speaking populations). Initially, Kingston was the principal city of the English half of the corridor, but eventually Toronto outgrew it.

During both the North American part of the Seven Years' War between Great Britain and France and the War of 1812 between United Kingdom and the United States, settlements along the corridor were at the centre of the conflicts. Ottawa was eventually chosen as Canada's capital by Queen Victoria precisely because it was further inland and thus less vulnerable to attack, though it is now also considered part of the corridor. The Rideau Canal was constructed to provide a way to bypass the most vulnerable part of the corridor, from Cornwall to Kingston, where it lies directly on the U.S. border.

The construction of the Saint Lawrence Seaway during the late 1950s made it possible for some ocean-going vessels to travel the full length of the corridor and beyond to the upper Great Lakes, but resulted in the destruction of several villages in the Eastern Ontario portion of the corridor.

The oldest transportation route is the St. Lawrence River and Great Lakes, where the series of channels and locks that make up the St. Lawrence Seaway allow ocean-going vessels and lake freighters to travel the entire length of the corridor.

Autoroute 73 entering Quebec City

Most of the cities of the Ontario portion of the corridor were originally joined by Highway 2 (often known locally by names such as "Montreal Road," "Toronto Road," or "Kingston Road") following the routes of older stagecoach roads and the paths and trails that predated them. Highway 2 still forms the main street of many of the corridor's Ontario towns and cities (which were built around it), but large parts of the highway are now maintained by counties or municipalities rather than the province. From 1938 to 1968 the province of Ontario built Highway 401, a freeway that, aside from running more northerly nearby Kitchener instead of through Hamilton, mostly follows a similar route to Highway 2 but bypasses most of the town and city centres. The 401 is now the main transportation route of the corridor up to the Quebec border, where it becomes Autoroute 20 and continues east through the Quebec part of the corridor to Quebec City. Highway 403, which connects to the 401 at both of its ends, largely follows the route of Highway 2 between Woodstock and Toronto including through Hamilton and acts as another important main transportation artery. Highways 416 and 417 link Ottawa to Brockville on the 401 and Montreal on Autoroute 20.

Via Rail Ocean Train route.

Both the Canadian National Railway (CN) and the Canadian Pacific Railway (CP) have extensive freight railway lines along the length of the Quebec City – Windsor Corridor. Intercity passenger railway service is provided by Via Rail throughout the region, mostly using CN freight lines. Referred to in Via Rail's published timetables as simply the Corridor, the Quebec City – Windsor Corridor is the busiest portion of the Via system, accounting for the majority of Canada's intercity passenger trains and ridership. About 67% of Via Rail's total revenue is earned on the Quebec City – Windsor Corridor. Prior to Via's formation in 1978, both CN and CP operated Corridor services.

Other inter-city trains from outside the region originate and terminate at cities in the Corridor, such as Via's Canadian, Montreal – Gaspé train and Ocean. Amtrak offers two international inter-city passenger railway lines that starts in New York City with one that ends in Toronto and the other in Montreal, serving cities along the Corridor as well as in Upstate New York.

There have been various proposals and studies for high-speed railway service along the Corridor.

The major passenger airports along the corridor are Toronto Pearson International Airport (ranked 20th globally for international passenger traffic and 18th for aircraft traffic ), Montréal-Pierre Elliott Trudeau International Airport, Ottawa Macdonald-Cartier International Airport, Québec/Jean Lesage International Airport, Hamilton/John C. Munro International Airport (ranked second in Canada for cargo traffic) and the military airbase at CFB Trenton.

Other civilian corridor airports with scheduled airline service include Windsor Airport, Sarnia (Chris Hadfield) Airport, London International Airport, Region of Waterloo International Airport, Billy Bishop Toronto City Airport, Kingston/Norman Rogers Airport, Lake Simcoe Regional Airport and Gatineau-Ottawa Executive Airport. Montréal-Mirabel International Airport is a large facility near Montreal that is mainly used for cargo flights but is also home to medical evacuation[3] and general aviation[4][5] flights.

Inside the corridor, the busiest area of travel is the Toronto–Ottawa–Montreal triangle. There are roughly 108 flights within the Toronto–Ottawa–Montreal triangle every work day, making it the busiest air route in Canada and 15th busiest air route in the world. Air Canada serves the three cities with its Rapidair service, offering hourly flights, and its principal competitor WestJet offers similar service. Air Canada and Porter Airlines fly from Billy Bishop Toronto City Airport to Ottawa and Montreal, while Air Canada Jazz offers commuter flights connecting many of the smaller airports to Toronto, Ottawa, and Montreal. In addition to scheduled air service, some of the airports along the corridor also have frequent charter flights like Air Transat and Sunwing to popular tourist destinations.