Some critics have alleged that the rerouting of State Highway 1 over the Auckland Harbour Bridge (to ensure toll revenues) was a primary contributor to the decades-long delays.

The rerouting is alleged to have significantly contributed to the need for a massive motorway through the centre of Auckland, severely damaging inner city suburbs such as Freemans Bay and Grafton.

[4] Construction of the Waterview Connection began in late 2011 and it was opened to traffic on 2 July 2017.

This completed the route as a highway, with a remaining section of SH 18 still to be upgraded to motorway standard.

The Upper Harbour Highway section was upgraded to motorway status as part of the Northern Corridor Improvements project.