New Zealand State Highway 18

State Highway 18
Route information
Maintained by New Zealand Transport Agency
Length:	14 km (9 mi)
Major junctions
East end:	SH 1 Northern Motorway, Meadowood, North Shore City
West end:	SH 16 Northwest Motorway, West Harbour, Waitakere City
Location
Primary destinations:	Greenhithe, Hobsonville
Highway system
New Zealand state highways Motorways and expressways List Unused ← SH 17 SH 20 →

File:Hobsonville, Rural Scenes Giving Way.jpg

The former route of State Highway 18, in 2010, was a mostly rural highway. This route is now designated Urban route 32.

File:Upper Harbour Motorway at Trig Road Interchange.jpg

The Hobsonville section of the Upper Harbour Motorway, looking west from the Trig Road Interchange

State Highway 18 (SH 18 also known as the Upper Harbour Motorway) is a State Highway linking North Shore City and Waitakere City in Auckland, New Zealand. It is the northern part of the Western Ring Route. State Highway 18 formerly ran along the Coatesville Riverhead Highway, further north than its current position.

Route

SH 18 begins at the Auckland Northern Motorway, as a dual carriageway road, heading west on Upper Harbour Highway, after two kilometres becoming a motorway at the Albany Highway interchange. This four-lane section of motorway opened in December 2007, and bypassed the single carriageway Upper Harbour Drive. The motorway heads south-west, crossing the upper reaches of the Waitemata Harbour over the Upper Harbour Bridge. At Squadron Drive, the highway extends onto a new section of motorway, which opened in August 2011, bypassing Hobsonville Road. This road cuts across in a southwestern direction across farmland to Westgate, where it turns southward and merges with the Northwestern Motorway (SH 16) southbound. Motorists wishing to travel north onto SH 16 can cut across by taking the Brigham Creek Road exit.

Interchanges

Territorial authority	Location	km	#	Destinations	Notes
Auckland - Upper Harbour Board	Unsworth Heights	0.0		SH 1 Northern Motorway (south) – Auckland SH 1 Northern Motorway (north) – Whangarei	SH 18 ends
				Caribbean Drive
				Paul Matthews Drive
				Unsworth Drive	Westbound exit only
		2.4	2	Route 26 Albany Highway	Motorway ends
	Greenhithe	4.3	4	Greenhithe Road	Eastbound exit and westbound entrance
		6.2	6	Tauhinu Road	Westbound exit and eastbound entrance
		7.4		Upper Harbour Bridge over Waitemata Harbour
	Hobsonville		8	Squadron Drive	Westbound exit and eastbound entrance
			9	Brigham Creek Road – Whenuapai, Helensville	to north
			10	Trig Road	Westbound exit and eastbound entrance
Auckland – Henderson-Massey Board	Westgate		11	Route 32 Hobsonville Road	Westbound exit and eastbound entrance
				SH 16 Northwest Motorway (south) – Waitakere, Auckland	SH 18 ends
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

Cycleway

The route of the new motorway from Upper Harbour Bridge to Westgate was originally to receive a cycleway as well, but although the land was set aside, there is no timetable for the construction of the route.

See also

• List of New Zealand State Highways