I'm a little confused. It looks like the author compares the average road expenditures to the specific road costs per resident in a cul-de-sac, and finds that c

I'm a little confused. It looks like the author compares the average road expenditures to the specific road costs per resident in a cul-de-sac, and finds that cul-de-sac residents require a disproportionate expenditure. That's kind of obvious. Lower-density residents require more roads. But "disproportionate" is different from "insolvent". The analysis doesn't close the loop on tax revenues vs. expenditures.