State Highway 18 (New Zealand)
| State Highway 18 | ||||
|---|---|---|---|---|
| Upper Harbour Motorway | ||||
| Route information | ||||
| Maintained by NZ Transport Agency | ||||
| Length | 14 km (8.7 mi) | |||
| Major junctions | ||||
| North-east end | SH 1 (Auckland Northern Motorway) at North Shore | |||
| South-west end | SH 16 south (Northwestern Motorway) at West Harbour | |||
| Location | ||||
| Country | New Zealand | |||
| Primary destinations | Greenhithe, Hobsonville | |||
| Highway system | ||||
| ||||
State Highway 18 (SH 18), also known as the Upper Harbour Motorway, is a state highway that runs between the Auckland Northern Motorway (SH 1) on the North Shore and the Northwestern Motorway (SH 16) in West Auckland, New Zealand. SH 18 forms the northern part of the Western Ring Route, which continues from Waitakere south-east to Manukau.