That doesn't change the incentives though - the taxes are there for a reason.
EDIT: what I mean is that removing the petrol taxes won't solve the set of environmental and political problems they face, but rather would likely make them worse.
Their shipping and distribution costs are quite different though. Petrol taxes also tend to be flat - advocates for removing them always crop up, but it's a suckers bet - you wipe out say, your road maintenance income, for (in Australia) a onetime 17c on the liter drop in price (while the price just keeps going up anyway).
