Prior to the construction of Highway 410, Heart Lake Road was flanked by the industrial lands of Brampton and Bramalea north of Steeles Avenue, which required the highway to follow the road's alignment to avoid demolition of buildings. Between Steeles and Highway 401 was agricultural lands, allowing for the highway to constructed on a separate alignment to the west. In 1975, construction began on the widening of Highway 401 between Highway 10 (Hurontario Street) and Highway 427. During this expansion from four to six lanes, directional ramps were constructed with the new road to allow access to and from Toronto.