State Highway 73 (SH 73) is a major east-west South Island state highway in New Zealand connecting Christchurch on the east coast with Cass/Hokitika via the Southern Alps. It is mostly two lane, with some single-lane bridges north of Springfield but is mostly dual carriageway in Christchurch. The fourth and fifth-highest points of New Zealand's state highway network are on this road at Porters Pass and Arthur's Pass respectively.