[4] The route largely parallels a now abandoned branch of the Canada Southern Railway which ran from St. Thomas to Courtright.

Between there and the community of Kimball, the route veers several times, a realignment which improved the highway’s crossing of the now abandoned railway.

Between Brigden and former Highway 21 at Oil City, the route crosses a flat agricultural area and encounters the historic Sarnia Plank Road.

[5] East of Oil City, Highway 80 continues through a large swath of farmland, passing south of the communities of Glen Rae, Weidman and Inwood.

Prior to crossing the Sydenham River and entering Middlesex County, the route encounters former Highway 79 south of the town of Alvinston.

[6] However, this winding route proved to be too dangerous and difficult for the explosion of vehicle traffic that occurred after World War II.

Courtright Line, which ended at Cameron Road and did not cross the Sydenham River, was chosen as an ideal route to extend east.

[5] The following table lists the major junctions along Highway 80, as noted by the Ministry of Transportation of Ontario.