Northwest Motorway

Northwestern Motorway
State Highway 16
The motorway west of Waterview
Route information
Maintained by NZ Transport Agency
Length:	21 km (13 mi)
Existed:	1952 – present
Major junctions
East end:	SH 16 Stanley Street at Auckland City Centre
	SH 1 Northern Motorway/Southern Motorway at Auckland City Centre
West end:	Brigham Creek Road, Whenuapai
Location
Primary destinations:	Central Auckland, West Auckland
Highway system
New Zealand state highways Motorways and expressways List Unused

The Northwestern Motorway (also known historically as the Auckland–Kumeu Motorway), part of State Highway 16 (SH16), is the major western route and secondary northern route out of Auckland in New Zealand. Twenty-one kilometres in length, the motorway runs from Stanley St in Parnell through the Central Motorway Junction, and west through urban Auckland and Waitakere before continuing northwest and terminating outside of Kumeu. Its western terminus is at Brigham Creek Road in Whenuapai. A large part of it forms the middle section of the Western Ring Route.

The first section of the Northwestern Motorway, to Te Atatu, was finished in 1952. The next section opened for traffic in 1955, then offering a two-laned 7.8 km section from Great North Road (current Exit 8) to Lincoln Road (current Exit 16). The section involved bridges over inlets of the Waitemata Harbour, which cut the journey between central Auckland and its airport at Whenuapai by 8 km. This section was later upgraded to four lanes.

In 1957, the motorway was extended westwards by one km to Lincoln Park Avenue, between the current Lincoln Road and Royal Road interchanges. In 1961, it was extended again by 2.7 km to its current terminus on Hobsonville Road at Westgate. Traffic could now travel 11.5 km on the Northwestern Motorway, and the journey between Auckland and Whenuapai was cut by a total of 9 km compared with local roads.

In 1966, the current Auckland International Airport opened at Mangere, and Whenuapai reverted to a military airport. This affected the use of the motorway, delaying further extensions.