One person died on the roads over the long Queen's Birthday weekend, and that low figure may be down to sheer luck, according to police.

The person was killed in a crash early on Saturday morning on the Waikato Expressway.

There was a second death in Canterbury, where the car crashed into a river in Amberley, but the car was 'off road' so will not be included in the official toll. The victim was a seven-year-old boy.

The toll is lower than in previous years, with three deaths over Queens Birthday last year, and six in 2020.

Director of the National Road Policing Centre Steve Greally told Morning Report the statistic may come down to luck and that it's hard to know what accounted for the low fatality rate during this year's holiday weekend.

"We really did have bad weather across most of the country, which you would have thought would go against us, but it is a really pleasing result in some respects," he says.

"When you think about the fact we had three people die last year and three before that, six before that... Sometimes it comes down to luck.

The weather may have played a factor, but he draws nothing conclusive from weather events in general.

"You get your ups and downs with the weather. Sometimes you can have beautiful weather and of course that attracts more people out on the roads and we have more carnage during that time. It's a really hard one to pick, when think about it's pouring rain, I'd like to think people are doing the right thing - they are slowing down to the conditions."

Even one fatality is too much, says Steve, as the human tragedy behind the statistic is all too clear.

"But when you think about whether it's a good result we really need to be thinking about the family of that person who did lose their life in Waikato.

"That's extremely hard for them to take. No take no comfort whatsoever that we had one fatality on our roads because it's affected them, their friends and the person's work colleagues so profoundly."

-RNZ.