[zanny]

It isn't even just active money used against suburbia, but the subsidization of urban sprawl by giving everyone "free" roads. In practical economics, it tremendously subsidized the capacity for people to live in suburbia to not have to build and maintain the roads that lead to their doorsteps, and instead let that burden fall to the common man. They weren't making the economic choice to live compact and not pay for connection to the outside world, because the public purse did it for them.

[grannyg00se]

I know nothing of this but I figured that when you build up a new subdivision as a developer you are responsible for the road construction leading to and within the new site. Is that not the case? You just build 200 homes and the government has to pay for all of the infrastructure? Connecting municipal utilities I thought would also be part of the developer's cost - which gets passed on to the home purchasers. So there would not be a "free" road for everyone.

[seanmcdirmid]

Developers have to pay development fees to cities, who then provide the services. Roads are probably a bit more complex because they are capital intensive, but zoning rules are supposed to keep development in check in this case. A town/city can decide to "expand", perhaps with developer prodding, and in some cases the other way around.

Detroit was utterly killed by its suburbs combined with white flight accelerated by the race riots of the late 60s.