Why is "Ontario Highway 400" trending?

Wikipedia Overview

King's Highway 400, commonly referred to as Highway 400, historically as the Toronto–Barrie Highway, and colloquially as the four hundred, 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 Parry Sound District in the scenic and sparsely populated central and northern regions. The portion of Highway 400 between Toronto (Highway 401) and Lake Simcoe roughly traces the route of the Toronto Carrying-Place Trail, a historic trail between the Lower and Upper Great Lakes. The full route of Highway 400 is part of the broader National Highway System. 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 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 in Toronto, where the speed limit is 80 km/h (50 mph) and the 60-kilometre (37 mi) stretch between MacTier and Nobel, where the speed limit was raised to 110 km/h (68 mph) on April 22, 2022.