Part of Hawke's Bay Expressway was closed for up to seven hours as police scene investigators tried to establish a cause, before Napier City Council contractors resurfaced the road.
Motorists wanting to travel north of Napier were recommended to take Poraiti Rd and then Glengarry Rd, and traffic was diverted through the airport.
The Watchman Rd and Meeanee Quay roundabout was also closed for northbound traffic.