The local–express lane system is an arrangement of carriageways within a major highway where long distance traffic can use inner express lanes with fewer interchanges compared to local traffic which use outer local lanes that have access to all interchanges. This can also be called a collector/distributor lane system within a single interchange. One of the longest examples is Highway 401 in Toronto, where highway ramps between express and local lanes cross over one another; these are commonly known as braided ramps.

King's Highway 400, commonly referred to as Highway 400, historically as the Toronto–Barrie Highway, and colloquially as the 400, is a 400-series highway in the Canadian province of Ontario linking the city of Toronto in the urban and agricultural south of the province with the scenic and sparsely populated central and northern regions. The portion of the highway between Toronto and Lake Simcoe roughly traces the route of the Toronto Carrying-Place Trail, a historic trail between the Lower and Upper Great Lakes. North of Highway 12, in combination with Highway 69, it forms a branch of the Trans-Canada Highway (TCH), the Georgian Bay Route, and is part of the highest-capacity route from southern Ontario to the Canadian West, via a connection with the mainline of the TCH in Sudbury. The highway also serves as the primary route from Toronto to southern Georgian Bay and Muskoka, areas collectively known as cottage country. The highway is patrolled by the Ontario Provincial Police and has a speed limit of 100 km/h (62 mph), except for the section south of Highway 401, where the speed limit is 80 km/h (50 mph).