The Macdonald Cartier Freeway
This plaque commemorates the completion of the Macdonald Cartier Freeway (Highway 401), the longest freeway operated without tolls by a single highway authority in North America
Covering 820 km between Windsor on the United States border and the Ontario-Quebec boundary, it serves the richest economic region in Canada.
In January, 1965, it was named by The Honourable John P. Robarts, Prime Minister of Ontario, in honour of the two founding architects of the Confederation of Canada, Sir John A. Macdonald and Sir Georges-Etienne Cartier.
This site is located on the last section of construction consisting of 24 km between Ivy Lea and Highway 2, which was completed on October 11, 1968.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.