We're not living in NZ yet, but I also live about 10 km from my workplace. If I go with the car it can easily take 30 or 40 minutes during peak commuting time, and if there's any kind of incident or heavy volume it wouldn't be too unusual for it to take an hour.
On the road bike, as it's a little bit of a climb, it takes me about 23 minutes to the office usually 18 minutes coming back. Plus I'm not using any fuel, I'm getting exercise, and I'm not as pissed off because I'm not sitting in traffic.
I'm probably one of the few people that welcomes higher fuel prices because it forces people to consider alternatives to commuting in cars by themselves.