Since rural roads get significantly less traffic, they require less maintenance (Though get similar amounts of frost heave damage). Maintenance is often just filling in potholes and cracks, with occasional resurfacing.
Of course, there are a ton of non-local funding that gets drawn from:
- federal and state gas taxes
- state vehicle registration fees (varying by type and weight of vehicle)
- state, county and municipal specific property, income and / or sales taxes
As for highways, there is the federal highway trust, and grants and loans can be taken out to pay for them, but that typically does not fall on the town's shoulders alone (if at all).