The head of the country's road policing says alcohol was a factor in three of the four fatal crashes this weekend, in which seven people have died.
In the latest crash in Hawke's Bay, four farm-hands died when the Mitsubishi four-wheel drive they were travelling in crashed through a fence and ended up in a paddock on Waikare Road, just off State Highway 2 near, Putorino.
A farmer came across the mangled vehicle while on the way to shift her cows at about 7.30am on Sunday.
Three of the men had been flung from the vehicle and all four were dead when emergency services arrived.
Police say the men, in their 40s and 60s, had been drinking at a local hotel.
Acting national road policing manager Rob Morgan says investigators believe people had also been drinking in two other fatal crashes this weekend, and that's frustrating.
He says warnings about drinking and driving in rural areas is an old issue that seems to still be ignored.
Superintendent Morgan says the police had been hoping for another zero-fatality weekend like Easter, which was the first time any holiday weekend had passed without people dying on the roads.
Police want to hear from anyone who may have seen the crash or the blue-grey Mitsubishi Pajero wagon in the northern Hawke's Bay area on Saturday.
The men's names won't be released until their families are notified.
The deaths bring to seven the number of people killed on the roads this Queen's Birthday weekend. Two pedestrians have been killed - at Lincoln in Canterbury about 2am on Sunday and at Otane in Hawke's Bay on Saturday.
A motorist died on Saturday after driving into a power pole at Stratford in Taranaki.