Central Motorway Junction
The Central Motorway Junction or CMJ (best known as Spaghetti Junction and rarely as Central Motorway Intersection ), is the intersection of New Zealand State Highways 1 and 16, just south of the central business district of Auckland, New Zealand. A multilevel structure (at least three traffic lanes crossing above each other in several locations), it has been described as a "fiendishly complicated, multi-layered puzzle of concrete, steel and asphalt". Carrying around 200,000 vehicles a day, it is one of the busiest stretches of road in New Zealand. The central motorway junction forms the intersection between the three major motorways of Auckland ( Auckland Northern Motorway (SH1), Auckland Southern Motorway (SH1), and Northwest Motorway (SH16)), and also offers several off-ramps for access from these motorways to the city centre. It is principally located in a series of gullies to the south and east of the CBD and in cuttings to the west. It has somewhat of a hybrid function, falling between a typical ‘X’ interchange and ring road around the city centre. However all linkages are direct and there is no separate ring road as such. The interchange and associated structures encircles the Auckland CBD on three sides, the Auckland waterfront to the north forming the fourth 'border' of central Auckland.

Designed in the 1960s, and with most of its links built in the 1970s, the junction was a major project in a scheme that forced over 50,000 people to move from the area when the central motorway network was constructed, with major effects on the nearby Karangahape Road shopping area. The junction was substantially extended (or in a sense, finally completed) in the 2000s, with the final links opened to traffic in December 2006. During the duration of this NZ$208m project, the existing motorways had to be closed several hundred times during nighttime, with traffic rerouted over local roads.

The Central Motorway Junction provides direct motorway-to-motorway links between the following four routes radiating from the city centre:
  • Auckland Northern Motorway (SH1) to/from North Shore City via Auckland Harbour Bridge
  • Auckland Southern Motorway (SH1) to/from Manukau City and
  • Northwest Motorway westbound (SH16) to/from Waitakere City
  • Northwest Motorway eastbound (SH16) to/from Ports of Auckland and eastern suburbs
The last of these links (Northwest Motorway eastbound to Auckland Northern Motorway northbound) officially opened on December 19, 2006, marking the full completion of the junction. Plans have now shiffted further north, with the proposed tunnel at the Victoria Park Viaduct being the last of a set of three major motorway projects in the area. In addition, the CMJ includes the primary dedicated city exits from SH1 and SH16 to downtown, Grafton Gully (being the first of the three large motorway projects, and containing the section of the Northwest Motorway between the Upper Queen Street bridge and The Strand in Parnell, and the Auckland Southern Motorway between Symonds Street exit and The Strand), with some five other pairs of ramps giving access to the central area. A noteworthy structural component of the CMJ is the area underneath Karangahape Rd, where some 19 lanes of traffic forming 9 distinct links pass through a very constrained cutting under the Karangahape ridge on a multi-level structure.

Alternative routes
The other two major motorways under construction in Auckland, the 'South-Western' and 'Upper Harbour' motorways, will, when completed, form a continuous link in the west of the city, providing an alternative to SH1, between Manukau and Albany. The goal is to provide traffic passing through Auckland, or starting or ending in Auckland's western suburbs, with an alternative high-speed route that bypasses the often congested motorways in central Auckland, including the CMJ.

Cycle path
The New Zealand Transport Agency is as of November 2009 investigating a plan to extend the off-road Northwestern Cycleway through the intersection, to join it to Symonds Street and achieve better cycle linkages from the west into the Auckland CBD. In mid 2010, it became public that a preliminary alignment had been chosen, with the cycle path using a facility on the existing Upper Queen Street road bridge to cross the motorway.

Building Activity

  • removed a media
    about 6 years ago via OpenBuildings.com