A crash on the Auckland Harbour Bridge has also blocked one of three lanes, disrupting southbound traffic.
Motorists should expect delays from Esmonde Rd and are advised to pass with care.
On the Southern Motorway, drivers are also facing heavy congestion between Redoubt Rd and Great South Rd.
Traffic is also reportedly heavy along State Highway 2 through Maramarua, as well as on State Highway 1 between Huntly and Taupiri.
It is expected to be heavy most of the day on the Kapiti Coast through Paekakariki and between Peka Peka to Otaki and for motorists heading out of Wellington.
Road users are advised to expect delays and allow extra time for their journeys.