Ontario Highway 400

Highway 400
Toronto–Barrie Highway[1]
Highway 400 highlighted in red
Route information
Maintained by Ministry of Transportation of Ontario
Length	226.0 km[2] (140.4 mi)
History	Opened December 1, 1951 – July 1, 1952[3]
Major junctions
South end	Maple Leaf Drive – Toronto (continues as Black Creek Drive)
Major intersections	Highway 401 – Toronto  407 ETR – Vaughan  Highway 11 – Barrie  Highway 12 – Waubaushene  Highway 124 – Parry Sound
North end	Highway 69 – Carling
Location
Country	Canada
Province	Ontario
Divisions	York Region, Simcoe County, Muskoka, Parry Sound District, Sudbury District (future)
Major cities	Toronto Vaughan Barrie Sudbury (future)
Towns	Parry Sound, Bradford, King
Highway system
Ontario provincial highways Current Former 400-series
← Highway 148 → Highway 401
Former provincial highways ←  Highway 169 Highway 400A  →

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) and the 60 km (37 mi) stretch between MacTier and Nobel, where the speed limit was raised to 110 km/h (68 mph) on April 22, 2022.^[4]

Although part of the Trans-Canada Highway only over the portion between Highway 69 and Highway 12, the full route of Highway 400 is part of the broader National Highway System.

It was the first fully controlled-access highway in Ontario when it was opened between North York and Barrie on July 1, 1952. On that date, it was also the first highway to be designated as a 400-series. The freeway was extended in both directions; north of Barrie to Coldwater in 1958, and south of Highway 401 to Jane Street in 1966; a short distance east of Jane Street the route continues as the municipal expressway Black Creek Drive which opened in 1982. Since the 1970s to the present there have been numerous projects which have widened and modernized the freeway between North York and Barrie, including being expanded with a collector-express system in Vaughan to accommodate the interchange with the new Highway 407 ETR.

Highway 400 is the second longest freeway in the province, the trans-provincial Highway 401 being the longest. Since 1977, construction on the freeway has been snaking north along Highway 69 towards Parry Sound and Sudbury. As of 2011, a four lane freeway is opened as far north as Carling; at that point, the four lanes narrow into two and continue northerly to Sudbury as Highway 69. At the north end of Highway 69, a segment of freeway is in operation from near Highway 522 south of the French River to Sudbury; while this section will be part of the completed Highway 400 route, at present it remains signed as Highway 69. The remaining gap between Carling and Highway 522 will be opened in stages as construction is undertaken and completed.^[5]