The NZ Transport Agency says all southbound and northbound motorway lanes on State Highway 1 have re-opened at St Marys Bay near the Auckland Harbour Bridge.
Some lanes in both directions had been closed for several hours after a Police incident in the area.
The Transport Agency says although lanes have re-opened, it will take some time for northbound congestion in particular to clear.
A queue of slow moving northbound traffic had extended south of the Greenlane interchange during the incident.
The Transport Agency says drivers heading north have the choice of avoiding delays by using the Southwestern and Northwestern Motorways and re-joining SH1 at Albany, or to use the Curran Street on-ramp to access the Auckland Harbour Bridge.
Southbound traffic is flowing relatively freely.