SH 16 begins in Central Auckland at the corner of
The Strand,
Tamaki Drive and
Quay Street, directly opposite the
Port of Auckland. It travels south via The Strand where it reaches the lights at Beach Road and Parnell Rise where it changes to Stanley Street. After one more set of lights at Alten Road, SH 16 becomes coextensive with the Auckland Northwestern Motorway. The highway travels through the
Central Motorway Junction where there are exits to both northbound and southbound. It then runs west and forms a junction with and then continues to
West Auckland over a causeway crossing Traherne Island and the
Whau Estuary. SH 16 then passes through West Auckland and past the junction with (Upper Harbour Motorway) where it can be accessed by northbound traffic. The Northwestern Motorway terminates at a roundabout with Brigham Creek Road and Fred Taylor Drive. From here SH 16 reverts to single carriage road. It passes through the communities of
Kumeū,
Huapai,
Waimauku and
Helensville, eventually reaching the west coast. From there on SH 16 skirts the
Kaipara Harbour along the Kaipara Coast Highway, eventually bearing northeast to meet SH 1 at Wellsford, where it terminates. ==Major intersections==