Street (former Highway 40B) and a former railway line. Running north of the former Holmes Foundry (closed in 1988 by owner Chrysler), the route then becomes parallel to and north of Exmouth Street as it dives under the Christina Street overpass and enters the City of Sarnia. East of the Murphy Road underpass, the freeway curves to the northeast to bypass its original alignment. It crosses the Howard Watson Nature Trail, a mixed-use recreational trail that was converted from a Canadian National Railway (CNR) line in 1988. The highway curves back to its east–west orientation at an interchange with Highway 40 (Modeland Road). It passes south of Sarnia Chris Hadfield Airport before exiting the city limits at Mandaumin Road (Lambton Road 26). Now parallel and north of London Line, the former route of Highway 7 (the predecessor route between Sarnia and London), the freeway jogs north to travel along the back lot line of farmland fronting London Line and the concession road north of Highway 402.The highway split at least one farm in half during its construction, with the family’s barn being burned down to make way for the construction. The freeway passes by a truck inspection station (eastbound traffic only) and truck rest area (westbound traffic only, formerly a truck inspection station) before being crossed by Camlachie Road. It meets Lambton County Road 21 (Oil Heritage Road), the northern terminus of the Oil Heritage Route, north of the town of Wyoming. The county road is also a former southern extension of Highway 21, which itself begins as Forest Road to the east. Highway 21 is also known as the Bluewater Route, as most of its length is parallel to the shore of Lake Huron. After passing an interchange with Forest Road, the freeway is crossed by London Line and momentarily diverges from its straight alignment to dip south of Warwick. It continues east through large patches of farmland, then meets with Middlesex County Road 81 (Victoria Street) at an interchange as it passes north of Strathroy. Shortly thereafter it curves to the southeast and zig-zags towards London, bisecting farms and dividing woodlands. The freeway passes to the west of the town of Delaware and curves east. It enters London and meets interchanges with Highway 4 south of Lambeth, as well as with Wonderland Road before merging into Highway 401. Access to westbound and from eastbound Highway 401 is provided