Technology shapes our lives and even our cities in ways we often don't suspect. Everyone knows that automobiles drove the expansion of suburbs, but there are other examples. Before the widespread adoption of elevators, for instance, rich and poor were often segregated vertically; the young and poor climbed many flights of stairs to the top of apartment buildings; as they rose in the world and in years they would pay the much higher rents the lower floors commanded. As a result, rich and poor had many interactions that are much less likely with today's separation of many miles between desirable suburbs and miserable inner-city slums or impoverished rural areas.
Especially in America today, automobiles and freeways and suburban zoning have made Michael Harrington's 1960's vision of _The Other America_ even more extreme than he imagined: "Two nations, separate and unequal." People who grow up today in wealthy suburbs, tens of miles from any trace of poverty, are physically and psychologically almost completely separated from the desperate existence of people in that other country. The potential benefits of their better education and different outlook and willingness to help rarely connects with them. Former President Jimmy Carter wrote in his memoirs that he, growing up in a legally segregated South in the 1940's and 1950's, had far more contact with poor blacks than he sees today. He had black friends as a child and slept over at their houses; this kind of informal interaction is far less likely today because of the physical separation of suburb and ghetto. Similarly the poor, unable to reach jobs and opportunities available in the faraway suburbs, not only lose out themselves but cannot contribute to the whole economy and country as they could 50 or 100 years ago.
By making cities desirable places to live AND manufacture, SkyTran and its side effects such as ExtremeCustomization will provide an incentive for rich and poor to live in the same metropolitan area, although probably not next door. (Automatically programmed vehicles can control access with magnificent precision, by mechanisms such as the portal credentials we proposed for SafeTran and IndependentHandicapped -- see WhoControlsVehicles.)
Gentrification and the revival of urban areas is already a major trend in America. By itself, SkyTran's rapid commuting without congestion and parking problems will make dense cities much more livable, dramatically accelerating this trend. However, not only will unmatched convenience and sophisticated services attract the rich, but convenient public transportation throughout a metro area and efficiencies of manufacturing that tend to move jobs there will also draw large numbers of poor working people to move back to cities. Phenomena like ExtremeCustomization, FrictionFreeCapitalism, and ExtremeJustInTime (besides managing all the SuperSevenEleven stores and local delivery services) will open many thousands of jobs all over cities to anyone with decent character and a willingness to work.
As population densities increase and desirable places to work, live and play become abundant in a smaller area, average trip lengths will decrease as as some power of the increase in density (now there's a good modeling project for a sociologist!). Together with less heating and cooling costs in denser housing, less fertilizer spread on small condominium lawns instead of suburban acreage, etc., resource consumption and environmental damage will ease substantially, together with the geopolitical tensions around oil.