what is its route description?
Beginning at the St. Clair Parkway near the shores of the St. Clair River, the route travelled , intersecting Highway 40, Highway 21 and Highway 79 before ending at Highway 2.
Ontario Highway 80
 It travelled in an east–west direction south of Sarnia from Courtright to Strathburn. Beginning at the St. Clair Parkway near the shores of the St. Clair River, the route travelled , intersecting Highway 40, Highway 21 and Highway 79 before ending at Highway 2.
what is ontario highway 80? It was a provincially maintained highway.
wiki:18478454
Ontario Highway 80 [SEP] Introduction
Most of the original winding highway was bypassed in 1962, and the route was extended west in 1963 to what was then Highway 40, now the St. Clair Parkway. It remained this way for over 30 years before being decommissioned as a provincial highway entirely in the mass downloading of highways in 1997. Today the route is known as County Road 80.