Police in Auckland have closed the Ellerslie interchange northbound onramp on the Southern Motorway to deal with a crash that was initially reported to have been fatal.
A man was taken to Auckland Hospital in a serious condition. A stroke or heart attack was thought to be the likely cause of the crash, police said.
Drivers have been advised to take particular care on the interchange because of poor weather conditions.
The bad weather has also led to Auckland police receiving calls about flooding and waves breaking over parts of Tamaki Drive.
Police are advising drivers to avoid Tamaki Road between Mechanics Bay and Ngapipi Road.
There have also been reports of boats breaking loose from their moorings and being blown onto rocks at Okahu Bay.
Meanwhile, just north of the city, Search and Rescue and the Coastguard were attempting to rescue two people, believed to be husband and wife, from rocks in Whangaparoa.
The Westpac helicopter was unable to take to the air due to the high winds and heavy rain.