$7.26 USD/gallon according to Google's latest exchange-rate thingy, but what is neglected is that New Zealand has at least four advantages that the US does not:
1) geographic size - infrastructure costs have to be orders of magnitude smaller.
2) smaller population, ergo less automobiles to pound on the aforementioned roads
Those two tend to cancel out. Yes, we've got less land area, but we've also got less people to pay for it. According to Wolfram Alpha, the population density in the US is double that of New Zealand.
3) the population is mostly concentrated in a couple of cities, and not of a huge relative geographical area. More folks can do mass transit there, and drive less often.
I wish. There is actually a substantial number scattered all over the country. The land was divided recently, so everyone got their block, which got divided several times for their children. One of the big hazards when driving is the numerous driveways everywhere. So cars became the norm. Public transport is good in the city, but it's certainly not mass transit. Outside the city there are a few bus routes, once an hour. Trains (outside the city) are for tourists. The only passenger trains we get here are for the annual steam run.
I wish we'd get serious about railways. We seem to treat them as buses on rails, going 40mph tops and winding all round the suburbs. It's very difficult to get around here without a car. I'd love to use my bicycle, but there are big hills in every direction, and that seems to be the norm here!
4) an immigration policy that would get us called Nazis if we implemented them here (see also the current immigration woes and their contribution to economic issues here in the US)
We have more Chinese than Maori. Didn't seem to stop them!