South Eastern Freeway is a 73 km (45 mi) freeway in South Australia (SA). It is a part of the National Highway network linking the state capital cities of Adelaide, SA, and Melbourne, Victoria, and signed as National Highway M1. It carries traffic over the Adelaide Hills between Adelaide and the River Murray, near Murray Bridge, where it is connected via the Swanport Bridge to the Dukes Highway, which is the main road route to Victoria. It was formerly signposted as Princes Highway, which refers to the coastal route from Adelaide to Sydney via Melbourne.