If you had to pay the real bill for road maintenance alone suburbs would no longer be viable.
So the suburbs take from the commons and don't give back in your example.
Looking at a random SF suburb, "Pleasanton" [0] - it looks like 72% of their budget is funded through taxes and only ~7% is transfer payments.
[0] https://www.cityofpleasantonca.gov/assets/our-government/fin...
If you had to pay the real bill for road maintenance alone suburbs would no longer be viable.
So the suburbs take from the commons and don't give back in your example.