400-series highway

The **400-series highways** are a network of controlled-access highways throughout the southern portion of the Canadian province of Ontario, forming a special subset of the provincial highway system. They are analogous to the Interstate Highway System in the United States or the Autoroute system of neighbouring Quebec, and are regulated by the Ministry of Transportation of Ontario
 (MTO). The 400-series designations were introduced in 1952, although Ontario had been constructing divided highways for two decades prior. Initially, only Highways 400, 401 and 402 were numbered; other
designations followed in the subsequent decades.

Modern 400-series highways have high design standards, speed limits
 of 100 kilometres per hour (62 mph) (a 110 km/h trial is taking place on select stretches), and various collision avoidance and traffic
management systems. The design of 400-series highways has set the
precedent for a number of innovations used throughout North America, including the parclo interchange and a modified Jersey barrier design known as the Ontario Tall Wall. As a result, they currently experience the lowest accident and fatality rate comparative to traffic volume in North America.

## History

When the 400-series designations were first applied to Ontario freeways in 1952, several divided highways had already been opened in Southern Ontario. Originally inspired by German Autobahns, Minister of Highways Thomas McQuesten planned a network of "Dual Highways" across the southern half of the province during the 1930s. The Queen Elizabeth Way (QEW) was first, an upgrade to the partially constructed Middle Road in 1934. McQuesten also sought out the economic opportunities that came with linking Toronto to Detroit and New York by divided roadways with interchanges at major crossroads. Although he
no longer served as Minister of Highways by the onset of World War II,
 his ambitious plans would come to fruition in the following decades as
Highways 400, 401, 402, 403 (between Woodstock and Hamilton), and 405.

The construction boom following the war resulted in many new
freeway construction projects in the province. The Toronto–Barrie Highway (Highway 400), Trans-Provincial Highway (Highway 401), a short expansion of Highway 7 approaching the Blue Water Bridge in Sarnia (Highway 402), and an expansion of Highway 27 (eventually designated as Highway 427 by
the mid-1970s) into part of the Toronto Bypass were all underway or
completed by the early 1950s. Seeking a way to distinguish the controlled-access freeways from the
existing two-lane King's Highways, the Department of Highways created
the 400-series designations in 1952. By the end of the year,
Highway 400, 401, and 402 were numbered, although they were only short
stubs of their current lengths. Highway 401 was assembled across the province in a patchwork fashion,becoming fully navigable between Windsor and the Quebec border on November 10, 1968; Highway 400 was extended north to Coldwater on Christmas Eve 1959; Highway 402 was extended to London between 1972 and 1982.

In addition to this network backbone, plans for additional
400-series highways were initiated by the late 1950s, comprising the
Chedoke Expressway (Highway 403) through Hamilton; the Don Valley Parkway Extension (Highway 404) northward from the soon-to-be constructed Toronto expressway; Highway 405 to connect with the American border near St. Catharines; Highway 406 south from St. Catharines to Welland; Highway 407 encircling the Greater Toronto Area (GTA), though not built for another 40 years; Highway 409 to connect Highway 401 with Toronto International Airport; and The Queensway (Highway 417) through Ottawa. The first sections of these freeways were opened in 1963, 1977, 1963, 1965,1997,1974, and 1960, respectively.

Throughout the 1960s and 1970s, additional freeways were planned or built, including Highway 427 in Toronto, Highway 403 through Mississauga, Highway 410 north to Brampton and Highway 416 to connect Highways 401 and 417. Highway 420 was designated in Niagara Falls,
though it had been built as part of the QEW in 1941. Other major works included the skyway bridges along the QEW and the
expansion of Highway 401 through most of Toronto into twelve lane collector-express systems.

By the mid-1980s, the network had more-or-less taken its current shape, with only Highways 407 and 416 yet to be built. Instead, emphasis was placed on expanding existing routes to accommodate increasing traffic volumes. However, extensions of Highway 400 towards Parry Sound, Highway 403 between Woodstock and Hamilton,
Highway 404 towards Newmarket, and Highway 427 towards Vaughan were underway. By the end of the decade, construction of Highway 407 and Highway 416 had begun,
and Highway 410 was expanded from two to four lanes.
Highways 407 and 416 opened in the late 1990s. Until early 2015, Highways 407 and 416 were the most-recently designated
 (and constructed) freeways in Ontario. This has changed with the
designation of Highways 412 and 418. In addition to these new additions to the 400-series network, several
extensions of existing freeways have been built or are underway, including Highway 410 north of Brampton in 2009, Highway 400 to north of Parry Sound in 2010, Highway 417 to Arnprior in 2012, Highway 404 to Keswick in 2014, Highway 401 through Windsor in 2015,
and four-laning Highway 406 to Welland in late 2015.