Western Highway is a major arterial route in western Victoria with a length of approximately 258 kilometres (160 mi) of single carriageway, then 161 kilometres (100 mi) of dual carriageway known as Western Freeway, linking the western suburbs of Melbourne to the border with South Australia at Serviceton. It is the Victorian part of the principal route linking the Australian cities of Melbourne and Adelaide, and is a part of the National Highway network, designated routes A8 and M8. The western end continues into South Australia as Dukes Highway, the next section of the Melbourne–Adelaide National Highway.