Putting petrol taxes in context

I have long advocated roads should be user pays and until we get the technology to monitor and charge actual road usage, petrol tax is the closest we have to it.

People are focusing on the 6c/l extra petrol tax that will be in place in two years time, but overlooking that in many areas petrol prices would be increasing by up to 13c/l. A regional tax of up to 10c/l and an increase in national petrol tax of 3c/l.

Personally I think the level of petrol tax should vary automatically to fund all road projects that pass a certain benefit:cost ratio.