Ontario Highway 401

Ontario Highway 401, also called King's Highway 401, is a provincial highway in southern Ontario, Canada. It is 817.9 kilometres (508.2 miles) long. It starts near Ontario's border with Quebec, where the road is called Quebec Autoroute 20. The western end of the highway is in Windsor.

Macdonald–Cartier Freeway
Highway 401 within Ontario, Canada
Route information
Maintained by the Ministry of Transportation of Ontario
Length	817.9 km (508.2 mi)
History	Proposed 1938 Opened December 1947 – October 11, 1968
Major junctions
West end	Highway 3 to Windsor
Major intersections	Highway 402 in London  Highway 403 near Woodstock Highway 407 near Milton   Highway 403 / Highway 410 in Mississauga  Highway 427 in Toronto  Highway 409 in Toronto  Highway 400 in Toronto Don Valley Parkway / Highway 404 in Toronto  Highway 416 towards Ottawa
East end	towards Montreal, QC
Highway system
Ontario provincial highways Current Former 400-series
← →

Construction on the highway started in 1947. By 1952, three different parts of the highway were finished, with the three parts connected by 1964. In 2013, another part of the highway was started. This part would extend the highway to the New International Trade Crossing at the Canadian-U.S. border near Detroit.

In 2008, part of the highway between Trenton and Toronto was called the "Highway of Heroes". This was because many Canadian soldiers who were killed overseas arrived at the Trenton airforce base. Their bodies were then transported along the highway to Toronto.