Megapolitan America an excerpt from a new planners press book suggests a novel way to slice and dice our megacities and regions

The sooner the US recognizes that it has evolved into a nation of 20-some very densely settled economic engines, the better able it will be to sustain long-term economic development to mid-century and beyond. A common misconception about the U.S. is that it has low population density. This view is held even by some public policy experts, who argue that because we are so spread out, the country cannot support European-style passenger rail. Two-thirds of the US population lives on less than 20 percent of the privately owned land. The US is not so much a collection of 50 states, more than 3,000 counties, or more than 30,000 cities and places as it is a federation of 23 megapolitan areas composed of networks of multiple large metropolitan areas. A big difference between the continents, however, is that Europe has stopped growing, while the US is on track to gain 90 million more residents between 2010 and 2040.