A similar debate is happening in Australia, with the added complexities of federal vs state taxation models, and a nationally collected GST tax (VAT like) which is distributed to the states. Petrol (gas) taxation to consumers is a confusing topic with many people believing in lots of economies its a hypothicated tax, dedicated to roads and related costs. Well, it's not. It's not defined in legislation in the two economies I know of, which do this stuff. It may or may not meet road costs, or exceed road costs, or be less than road costs. In australia the only hypothicated tax, and there are disagreements about if it meets the bar or not, is the medicare levy. Everything else is consolidated revenue, no matter what you think they do with it.