Do they pay proportionally to the damage they cause to the roads?
No, they don't. That's the point. The increase in fuel usage is not tracked with the increase in road damage due to more massive vehicles.
the point is stupid though. It's like saying we have $100 to purchase groceries this month but because Junior didn't contribute his 25% that he eats, we will be perfectly fine with spending it on beer and smokes instead. Trucks pay more, maybe not as much as you want, but there is more than enough money collected to cover the amounts of damage done to the roads each year. The problems arise when new roads are created which are not yet paid for by use taxes, when money is siphoned off to pay for pensions or bike paths or housing instead of the roads. It's like saying we will ignore the government buying booze and smokes with the road money because trucks don't pay as much as you want them to.
Nope. The total revenues from fuel taxes aren't even enough for all of the necessary road spending,
I never said they were. I said they were enough to cover damage to the roads.
and nope, most road construction is private contractors, state pensions don't factor in nearly as much as graft and corruption from that,
It doesn't matter if the road construction is private, pensions are still being paid on state and local employees from the road funds and all you manged to do is show where more waste is reinforcing my point.
bike paths are a trivial expense that benefits the public at large,
Um.. no they are not. A bike path in the town nearest to where I live ended up costing over 10 million dollars just in real estate acquisitions for the 15 mile path to nowhere important. Then they had to build basically a single lane road because they expected emergency vehicles to be able to drive on it when people have accidents or heart attacks and so on on the paths. Add on several bridges, modifications to existing bridges, and I'm not sure what is trivial about it. Hell, look into the bike path around Louisville Kentucky, it's 110 miles and even created several parks in the process.
residential roads are kinda essential to the whole system working, those commercial trucks wouldn't be worth anything if their customers couldn't buy the products.
I don't know what gave you the idea I thought otherwise. Those residential roads need repairs just as much as highways where trucks go will need. The problem is they do not collect taxes on those roads like for highways and they should be paid out of local taxes seeing how each local residential road increases property values for the local government. Why should a truck who doesn't even drive on them have to pay to maintain them when your primary complaint is that trucks need to pay the amount of damages they create? When states spend the highway trust fund on local residential roads so developers do not have to build them, it takes away from the funding to maintain roads already being used.