Nobody witnessed the crash but a number of people were on the scene soon after.
They tried unsuccessfully to revive the man, who was the sole occupant.
The death follows two fatal crashes over the weekend.
Stacie Holland, a 20-year-old Waikanae mother, was killed after her car collided and a small truck collided on State Highway 1 north of Wellington.
Sergeant Mike George of the Kapiti police strategic traffic unit said Ms Holland's northbound car clipped the curb and she overcorrected, veering into the southbound truck at the Pukerua Bay overbridge about 4.30am yesterday.
The truck's occupants - a market gardener couple, aged 57 and 55 - were uninjured in the crash.
The Levin husband and wife had been heading towards Wellington to sell their produce at a Sunday market.
Mr George said speed and fatigue appeared to be factors and the serious crash unit was investigating.
Earlier, a 66-year-old man was killed after his ute plunged into the remote Poolburn reservoir in Central Otago.
David John Williams, 66, of Moa Creek, had been visiting friends in the area on Saturday night and was on his way back home.
Mr Williams, thought to be the sole occupant, was found dead in his submerged ute at around 1am yesterday.
Senior Constable Brett Pay of Alexandra police said it appeared the ute had left the road, gone down a steep bank, landed on its roof and then somehow flipped back on to its wheels, coming to rest in the water.
The deck of the ute was partially submerged but the cab was under water.
Mr Pay said one of the man's friends went outside after he had left and noticed something in the water. Her screams then alerted others who called emergency services.
Police have not ruled out alcohol as a factor but that would be for the coroner to determine.
The man's body and the ute were removed yesterday afternoon.
