pass over Muchea South Road and the Midland railway line. The highway then enters the Perth metropolitan region (the City of Swan LGA, or local government area) and provides a western bypass of the town of Bullsbrook. The highway curves back to the south to pass over a roundabout interchange with Neaves Road. After , Tonkin Highway passes over another roundabout interchange with Stock Road West on the eastern side and Cooper Road on the west. A Heavy Vehicle Inspection Area is located immediately to the south. After a further Tonkin Highway curves to the south-west, upon which the farmland that dominated the first section of the highway gives way to the more undulating and less fertile Bassendean dune system. The transition is marked by the presence of a fauna overpass crossing the highway. Just south of the overpass the highway starts skirting the western edge of the major suburb of Ellenbrook for the next . Ellenbrook to the Swan River Tonkin Highway then descends from the dunes to cross under a roundabout interchange with The Promenade to the east and Birralee Road to the west in Ellenbrook, after which it continues southwest and meets Gnangara Road at a parclo interchange. The highway then curves back to the south and passes between the suburbs of Cullacabardee and Whiteman, replacing a section of Beechboro Road North. The highway heads south to cross over Baal Street, after which another roundabout interchange is reached with Hepburn Avenue and the remainder of Beechboro Road North. After passing underneath Marshall Road, Tonkin Highway arrives at a major free-flowing combination interchange with Reid Highway, previously the northern terminus of the highway. The wiggle pole street lighting reappears here, though the lights are yellow in colour this time. The highway then gains an additional lane and continues southwards, forming the border between the residential suburbs of Beechboro and Noranda; after , the highway enters the City of Bayswater LGA. The highway travels south for to Benara Road, which Tonkin Highway passes under. The south-eastern corner of Noranda is south of the flyover, leaving the highway entirely within Morley. Tonkin Highway continues south through the residential area for , and reaches a roundabout interchange, with Morley Drive and Morley Drive East. Tonkin Highway continues southwards through a narrow S curve that realigns the highway further east. Partway through the curve, south of Morley Drive, the highway passes under