400 Level Highways including QEW
The 400-series highways are a network of controlled-access freeways throughout the southern portion of the province of Ontario, forming a special series of the Ontario provincial highway system.
The province's baseline standard for the construction of a 400-series highway (or any controlled-access freeway in Ontario) is an average traffic count of 10,000 vehicles per day. However, other factors are considered as well.
The "400-series" numbers were first introduced to designate the province's controlled-access highways. The "4" was intended to reflect that these were four-lane roads, although portions of these highways subsequently exceeded four lanes.
Although the Queen Elizabeth Way has no posted highway number, it is considered to be part of the 400-series highway network. The QEW was the first of the controlled-access highways to be constructed.