A police spokeswoman said neither driver was injured in the crash.
Two ambulances and a rapid response unit were dispatched to the scene alongside the Whangārei Fire Brigade.
Diversions were in place for more than two hours while emergency services and a clean-up team respond to the crash.
Northbounded drivers were re-routed via SH15 and SH14 through Maungatapere.
Southbound traffic was able to continue along SH1 but experienced long delays.
A witness at the scene said there was around 2km of backed up traffic as motorists were being diverted.
The road re-opened to southbound traffic shortly before 1pm.