[Zxian]

You need _some_ roads, but not to the extent of your typical suburban sprawl. Where I live (Vancouver, Canada), there are sufficient roads for most travel, but the city also has relatively high quality public transit and decent bike routes. I don't think GP meant that a city should have no roads, but rather that transportation infrastructure is almost always going to be an expenditure for a city. America has simply chosen to prioritize cars over other transportation options.

Higher density minimizes the need for cars.