Where do you believe OP mentioned anything exclusive about the federal government?
I didn't assume that, but I was pointing out that even for the smaller governments (who do pick up most of the tab), it's not a vast nor an unsustainable amount. If anything, the fact that the Federal gov isn't a big part of the picture shows just how (relatively) minor the cost is. State, and particularly local, governments can't print the funds they need out of thin air.
Even though that is clearly an opinion-based statement, it's objectively wrong. The vast majority (3/4) of highway/road spending is done by state and local governments, not Federal. For the states/local governments, the amount is usually about 6% of all spending. About double that of police, and 2/3rds of hospitals and higher ed.
It's not like roads don't also serve commerce. Even with robust rail infrastructure, that last-mile would require roads. 6% of the budget for something that benefits every single member of society in immeasurable ways seems like a pretty good deal to me.
https://www.urban.org/policy-centers/cross-center-initiative...