You sure it's the weather and not the weather plus dudes out in the rural areas doing 90 to nothing because you don't see another car for like an hour straight in some places?
I was once in a car heading for Wellington and the rain was like the goddamn ocean was falling out of the sky. I don't know how often it gets that bad, but considering how many other forces of nature (floods, volcanos, earthquakes, etc) can kill you in NZ I wouldn't be surprised if rain was high on the list.
Reminds me of the Billboard on the Simpsons. First it was for the Itchy and Scratchy Movie and then the Barbershop. Limitless possibilities for this after the road safety campaign ends. If you can guess what I'm thinking of, you're probably wrong