The load and traffic that a typical driveway sees is far less than what a city block would be expected to see. There's more concrete, rebar, gravel, etc for every square foot of surface. Interstate-grade highways have 8-10 inches of reinforced concrete. Driveways are typically 4 inches and are not reinforced.

The same goes for asphalt, if that's what they're using. It'll be cheaper because it's not designed to last as long, but the scaling factors hold.