I don't have a source for this handy and I can't look at the moment, so I could be misinformed, but I'm pretty sure I've heard in many different places that the

I don't have a source for this handy and I can't look at the moment, so I could be misinformed, but I'm pretty sure I've heard in many different places that the current fuel taxes in the US don't even come close to covering road maintenance costs. I wonder if some kind of weight + mileage tax would work better?