Staff are directing traffic where possible.
State Highway 2 also has several partial closures or traffic management in place.
On State Highway 2 between Athenree and Tanners Point Rds temporary speed limits of 70km/h are in place in various spots along with shoulder closures.
There are shoulder closures between Tetley and Aongatete Rds.
Further north, there is stop/go traffic management in place due to road works and delays up to 10 minutes are possible.
A motorist who passed the traffic said it was "crawling" from Esdaile Rd - beyond Omokoroa - into the city.
She said traffic was also slow northbound on the highway.
According to Google Maps, there is an 18-minute delay on State Highway 2 after the Youngson Rd junction. It has recorded the average speed as 19km per hour.
Earlier, four people were injured, one seriously, in a crash involving a car and a van on State Highway 29 near Belk Rd.
The road was closed but has since reopened.
More to come.
