Transportation analyst Alan Pisarski, author of the definitive research and analysis on U.S. commuting patterns, has written an important and penetrating "white paper" for the Heritage Foundation on housing/transportation tradeoffs. It's a "must read" for anyone who wants to be conversant in this issue.
Housing-transportation tradeoffs will loom large in the current transportation reauthorization debate. An important and driving justification for increased transit funding, at the expense of both mobility and highway spending, will be the supposed benefits from households locating closer to transit. They can, essence, offload the costs of transportation onto the general public by reducing their out of pocket costs from getting rid of their car and its expenses and using highly discounted transit services.
Alan's analysis is much to detailed and rich to summarize here, but let's simply say the data are pretty compelling that our nation's wealth and mobility are inextricably intertwined. Rising expenditures on transportation are not an inherently bad thing if we are getting a higher quality of life from that spending.