Great Western Highway is a 202-kilometre-long (126 mi) state highway in New South Wales, Australia. From east to west, the highway links Sydney with Bathurst, on the state's Central Tablelands.

The M4 Motorway is a 55-kilometre (34 mi) series of partially-tolled dual carriageway motorways in Sydney, New South Wales designated as route M4. The M4 designation is part of the wider A4 and M4 route designation, the M4 runs parallel and/or below ground to Great Western Highway, Parramatta Road and City West Link, which are part of route A44.