That depends on the the practices in that place. Many places have little no significant backlog and low expenditures. It’s all a matter of how the municipality contracts out the work, who gets the work and how, what work is prioritized etc.

Got an example? I'd like to see a low-density city that's actually been consistently able to pay for its road maintenance.

And not a place that only has relatively new roads, mind you: somewhere that's already had to go through the process of repaving them as they deteriorate at least once or twice.

Sure. For example, consider the municipality of Wenatchee, in eastern Washington. In 2021, street maintenance is 3.5% of entire municipal budget. Another 6% is for capital improvements for road infrastructure (e.g. installing new traffic lights, new sidewalks, etc), but capital improvements do reduce maintenance in areas where capital improvements were done, so let’s say that 5% of entire municipal budget goes for road infrastructure maintenance. That’s hardly a large maintenance burden.

As it happens, most places that are not having some unrelated problems, like eg. being depopulated after industrial collapse, can easily cover the road maintenance, considering how little they spend on it, compared to other items in the budget. If you don’t believe me, now it’s your turn to look at the data: pick a municipality with terribly maintained road, and tell me what percentage of their budget is spent on road maintenance.