The initial twinning of Highway 43 began in the early 1970s with the first segment, from Highway 16 to north of Highway 633 (then numbered Highway 33), open by 1974.
Twinning of Highway 43 then ceased for 15 years until a segment within Whitecourt from Govenlock Road/Mill Road, just east of the McLeod River, to east of 33 Street in Whitecourt's southeast end was opened by 1997.