The $NZ 50m ($US 40.7m) project involved the construction of a 2km branch from a junction with the Auckland - Hamilton line at Puhinui to a new station at Davies Avenue in Manukau, which is expected to become the second-busiest station in Auckland after Britomart.
The alignment closely follows the S20 highway, and has been designed to allow future electrification. Part of the line is laid in a 300m-long trench, which accommodates two platforms 6m below the surface. Commercial services will begin on the new line on April 15.
A $NZ 95m university campus and transport hub, which will accommodate a ticket office and other facilities, is still under construction and due for completion next year.
The Manukau Rail Link is the first new passenger line in Auckland since the completion of the Eastern Line in 1930.