However , while some preliminary work began in the early 1960s , it would take until 1968 for a preferred route to be announced , and until 1972 for construction to begin .
The Department of Highways announced its intent to extend the route to Highway 401 in 1957 .
While some preliminary work began in the early 1960s , it would take until 1968 for a preferred route to be announced , and until 1972 for construction to begin .
The Department of Highways announced its intent to extend the route to Highway 401 in 1957 .