The typical town springs up around a natural resource—a river, an ocean, an exceptionally deep harbor—or in proximity to a larger, already thriving town. Not so with “new towns,” which are created by decree rather than out of necessity and are often intended to break from the tendencies of past development. New towns aren’t a new thing—ancient Phoenicians named their colonies Qart Hadasht, or New City—but these utopian developments saw a resurgence in the twentieth century.

In P...