Hugely so— much of the density of Japan's cities today, and many traditional cities worldwide, comes from small single-family homes and apartment buildings. The

Hugely so— much of the density of Japan's cities today, and many traditional cities worldwide, comes from small single-family homes and apartment buildings. They just don't have parking lots and huge roads between them. High-rises aren't necessarily very dense, especially if they're surrounded by a lot of open land— for example, NYC's high-rise housing projects are often less dense than the low-rise apartment buildings they replaced.