One person is dead and two people are in Wellington Hospital in a serious condition after a two-car crash just south of Foxton on State Highway on Sunday evening.
The collision happened at 6.30pm, caused extensive delays and was being investigated by the Serious Crash Unit.
The crash was the second in less than two hours in the lower North Island on Sunday, exacerbating a long day of holiday traffic woes on the main state highway.
It also comes a day after police publicly urged drivers to take more care following a "truly horrific start to the holiday season" that saw four people die on New Zealand roads in less than 24 hours.
The latest crash on Sunday blocked the highway near the intersection of Newth Rd at Foxton, in Manawatū, about 6.30pm, the New Zealand Transport Agency (NZTA) said.
The highway was closed at this intersection and motorists were told to either follow the directions of emergency services on-site or delay their travel.
News of the crash came just 30 minutes after SH1 reopened following a serious crash near Te Horo on the Kāpiti Coast.
That two-vehicle crash completely closed SH1 between Te Horo Beach Rd and Te Hapua Rd about 4.30pm.
Emergency services were called to the scene along with the Westpac Rescue Helicopter. Police said three people sustained non-life threatening injuries.
Police also attended a crash on SH2, on the Upper Hutt side of the Remutaka Hill, at 7.30pm on Sunday.
One person was reported injured in the incident, which left the south-bound lane blocked.
BAD START GETS WORSE
On Saturday, Road policing national manager Superintendent Steve Greally said police were extremely saddened by four fatal crashes that had occurred in the 24 hours prior.
Three of the four fatal crashes took place in Canterbury.
A man died when his car crashed on the Christchurch Southern Motorway about 9pm on Friday. The next morning in the North Island, one person died and another was critically injured when their vehicle crashed on Te Puna Rd, near Tauranga, about 4.30am.
A woman also died when her car crashed off a bank on Bossu Rd, Banks Peninsula, about 12pm on Saturday. Just hours later, about 2.10pm, a person was killed when the van they were in rolled on Mount Cook Rd, north of Twizel. Another person was taken to hospital with serious injuries.
"We need to get the message through. When you're driving, you need to take on board the responsibility that goes with that," Greally said.
"We want everyone to make it where they're going safely, and to be around to spend the holidays with their loved ones."
Drivers needed to be fully alert, and not driving drunk, drugged or fatigued. Everyone needed to wear a seatbelt, he said.
HOLIDAY TRAFFIC HEADACHES CONTINUE
Sunday's crashes happened on yet another day when escaping Wellington, by road, for the holidays proved a difficult task as traffic congestion caused "significant" delays on SH1.
At midday, NZTA was warning motorists expect delays of between 30 and 45 minutes while travelling between Waikanae and Ōtaki.
"Road users are advised to plan their journey accordingly and allow extra time."
A few hours later those delays had increased to about 60 minutes, although the congestion had begun to ease before the serious crash at Te Horo.
On Friday, drivers encountered delays on SH1 between Porirua and Pukerua Bay during the afternoon, although these cleared to provide motorists with a relatively smooth journey in the evening.
Then on Saturday, northbound traffic was gridlocked north of the capital after a bus caught fire on the same highway near Porirua.
Police were forced to close a northbound lane near Aotea, in Porirua, after a bus caught on fire about 10.40am. The congestion had eased by early afternoon.