It doesn't matter that taxes do pay for road, etc. repair, any more than it matters that your income normally pays for your own home's repair and renovation. Just like if someone damaged your home, you could sue them for the repair costs, if you damage the guardrails, the state can ask you to pay for the repairs and sue you if you don't. Anyone who is at fault in damaging another's property, whether that other is a person, a private business, a nonprofit, or the government, is liable or responsible for the cost of the damage he or she does.