Why are people in New Zealand such bad drivers?

I'm British, and have been holidaying in NZ for a few days now. I'll probably get called a winging pom, fair enough, but the driving here is absolute madness. Learned the hard way that "if it's got a tray, stay away".

Not surprisingly, i've seen more accidents in a week here than I would see in an entire year in the UK. I was on a single lane highway today and was run off the road by the two trucks behind me. Not to mention being tail-gated every 10 seconds when I was literally driving at the speed limit or even a touch above.

What am I supposed to do here? Am I supposed to pull over when someone is up my arse or am I just being tail-gated as a way to give me permanent road anxiety?

And just for a comparison, these are the road deaths stats, so it's not just anecdotal

Per 100,000 inhabitants road death rate
7.33 NZ

2.61 UK

Per 1 billion vehicle km road death rate

7.2 NZ

3.8 UK

And that's with the UK having far narrower and windier country roads compared to NZ

Source: https://en.wikipedia.org/wiki/List_of_countries_by_traffic-related_death_rate