> roads are BY FAR the most expensive part of infrastructure you mentioned - and those are financed by gasoline taxes.

Do you have any sources for that? I'm in Australia, where fuel costs about twice what it does in the US. A decent portion of that is taxes/duties, but road spending is taken from consolidated revenue, and fuel taxes ultimately contribute a minority of the spending on roads. So unless the cost of fuel production is massively lower in the US, something doesn't add up.