The Washington Post covered an interesting study by the Chicago-based nonprofit Center for Neighborhood Technology. Basically, to determine the cost of housing, the authors included the costs of transportation along with the cost of housing. Some findings:
…the combined cost of a home that requires a longer commute by car might exceed that of a more expensive home within walking distance of transit.
“The farther you get out, the cost of transportation can double,” said Scott Bernstein, president of CNT. “Somewhere between eight and 12 miles out from the center . . . housing costs dropped precipitously, but transportation costs went way up.”
Larger urban areas such as New York, Chicago and San Francisco, with more established transit options, fared better than smaller cities where the car is still king. Even Los Angeles, the epitome of urban sprawl, ranked as more affordable than Knoxville, Tenn., Terre Haute, Ind., or Laredo, Tex.
A neighborhood was rated as affordable if the combined cost of housing and transportation was below 45 percent of income. Of 3,012 census blocks in the Washington region, which contains several of the highest-income counties in the country, 2,158 blocks were ranked as affordable.
Just to give you an idea of the tremendous costs of transportation, consider this assessment of the DC suburbs:
Washington regional numbers indicate 26.03 percent of household income goes to housing costs. But add in transportation and the number soars to 43.55 percent.
A home in Loudoun County eats up an average 28.72 percent of household income with transportation raising that to 55.87 percent. Montgomery County housing came in at 26.57 percent but rises to 45.91 percent with transportation costs added in. A home in Fairfax County soaks up 30.63 percent of household income but 49 percent with transportation costs tacked on.
In the Boston area, here’s what affordability looks like, once transportation is factored in:

Yellow regions have a cost of housing less than 45% of income; blue regions have a cost housing greater than 45% of income
Even though I want to deport everyone to urban hellholes think urbanization is a good thing, I didn’t think that Boston (or Cambridge) would be so affordable after adding in transportation, until I thought of my own experience. When I had a car in Boston, between parking, servicing, taxes, insurance, and driving, it probably cost me six to seven dollars per year. If I actually did more driving (as I did when I lived in Long Island), the total figure would increase a couple thousand dollars more per year. So while I pay more for housing (~30%), my transportation costs are less than one percent of my income.
In fairness, there is an income selection going on here: parts of cities are often not cheap (i.e., Back Bay is expensive), but, still, having to fork over an additional 20-25% of income for transportation is actually quite expensive (the linked website is pretty cool, and you can extrapolate this). I wonder if this is where some of the anti-tax anger is coming from–there is essentially an outer suburb and exurb ‘tax’ in the form of high transportation costs. This ‘transportation tax’ is actually higher than many households’ income taxes (and in many cases, income and payroll taxes).