High Quality Content by WIKIPEDIA articles! State Highway 73 (SH 73) is a major east-west South Island State Highway in New Zealand connecting Christchurch on the east coast with Greymouth/Hokitika on the west coast via the Southern Alps. It is mostly two lane, with some single-lane bridges north of Springfield but is mostly dual carriageway in Christchurch with some sections of the road currently being upgraded to motorway status.