The motorway forms the northern part of the 48-kilometre Western Ring Route. Once completed, the Western Ring Route will provide a strategic alternative to SH1 between Manukau City in the south and Albany in the north via SH20, SH16 and SH18.

The motorway will be constructed in three sections – Upper Harbour Bridge duplication, Greenhithe Deviation and Hobsonville Deviation. The duplication of Upper Harbour Bridge was completed in 2006 and the Greenhithe Deviation opened in December 2007. Construction of the Hobsonville Deviation will start in October 2008.

Upper Harbour Motorway and the Western Ring Route

SH18 Upper Harbour Motorway will form the northern part of the Western Ring Route. Once completed, the ring route will provide an alternative between Manukau City and Albany via the Southwestern Motorway (SH20), the Northwestern Motorway (SH16) and Upper Harbour Motorway (SH18) to the Northern Motorway (SH1) at Constellation Drive.

For more information on the Western Ring Route, visit www.transit.govt.nz/projects/wrrconsultation/