How Urban Are U.S. States?

This map from 2010 shows the percentage of the population of each state that is urban. Some of the results are odds with our intuition. While it isn't a full explanation, a lot of the red state, blue state divide is a rural-urban divide.

This in turn, sheds light on the use of transit in different places in the U.S. The West has lots of empty space. But the places with people in them are often urban and high density.