Der Feuervogel aufersteht.

The world population density appears to be much higher in Europe, China, and Japan. I found a map from 1994. The 2006 map is only by country, but displays the same trends. The major cities in the US are extremely spread out compared to Europe, China, India, and Japan. There's no reason not to have good public transit within major cities here, but between major cities it is less obvious.

--Beth