Even in this story, city currently spends 3.2M/year maintaining the roads. City has 15k housing units so city currently spends roughly $200/house on roads. It's $16/month. Author thinks city actually need to spend 4.2M - this is $280/year per house which is only $23/month. That's really not much even if cost need to be doubled. Hardly unaffordable. This is per dwelling - not even per person and does not count that commercial buildings pay more so residential rate is even lower.
Electric/water/sewers generally pay for themselves thru user fee - I think average is $20-60/month/house for sewer/water in US and electric is thru usage fee. School busing in rural setting is probably a bit more expensive but is still rounding error in overall school budget.
Everything else - school, governance, police, fire are probably about the same in rural areas and in the dense city. SF is a shit city with 15k/year spending per person and most rural/suburban areas are much nicer on a fraction of that spending.
Overall rural lifestyle does not cost much more than the city in infrastructure costs - and I did similar calculations for previous strongtown articles. On a feeling level it make sense that dense city should be cheaper but reality is frankly it's not.
US cities has a lot of problems but frankly cost of maintaining roads is not the thing that will bankrupt them.