I think there are a few problems with the math but the largest seems to be his costs seem out of whack.
Creating a new road is more expensive than any maintenance/entire repaving since it shouldn't need to be re-graded/piped/utilities dealt with/etc. Sunnyvale in California quotes a variety of prices for street maintenance up to reconstruction and none are over $7/sq foot.[1] And this is in California where constructions costs are usually high compared to the rest of the nation.
Creating a new road is more expensive than any maintenance/entire repaving since it shouldn't need to be re-graded/piped/utilities dealt with/etc. Sunnyvale in California quotes a variety of prices for street maintenance up to reconstruction and none are over $7/sq foot.[1] And this is in California where constructions costs are usually high compared to the rest of the nation.
[1] http://sunnyvale.ca.gov/Departments/PublicWork/StreetMainten...