George Harris
Engineer
A lot of hot air an statistic massaging and manipulation is completely unnecessary if you just look at these light maps. They tell us much of what we need to know. Also, recognize that using the population of entire states such as Texas is also misleading. The "Texas Triangle" Dallas-San Antonio-Houston definitely has a series of high density population areas that should easily support rail service, but once west of the Ft. Worth - San Antonio line, the population density drops dratically.If you look at the satellite "light maps" of the United States, you'll notice that there's a cutoff point several miles west of I-35 where the population density goes way down until you reach the West Coast. Other than several large and growing cities in the West like Denver, Albuquerque, Las Vegas, Phoenix or Salt Lake City, the west is pretty much desolate.
As an aside, looking at the "world at Night" map published a few years back, there were obvious differences based on economics as well. Africa is still, if not the Dark Continent, at least a darker continent when comparing light levels with population. But, there were two truly "slap you in teh face" political boundaries that truly are visible from space. Egypt and Sudan. The Nile Valley was defined by a distinct band of lights from the Mediterranean all the way to the Sudan boundry. At that point is cut off abruptly in a precise east-west line. The othere: North and South Korea. South Korea was well lighted to the level of Japan and Western Europe. North of the border, there were a few dim light spots. Even Pongyang was not very bright.