Tod Newcombe reports that the site "uses several sets of data to arrive at average transportation costs. They include money spent on car ownership for your community as well as public transit costs. Other data sets, taken from Census block group data, such as average commute times, job density, transit connectivity, and household income, are factored in."
Called Abogo, the site also calculates the average CO2 emissions related to transportation choice.
Over at the New York Times, reporter Tara Seigel Bernard talks with CNT head honcho Scott Bernstein:
"Abogo's Web site also provides a list of tips on ways to lower your costs. Reducing the number of miles you drive, for instance, may qualify you for a reduction on your insurance premium.
Ideally, Mr. Bernstein said you want to ask yourself this question: Can I spend most of my money within walking distance of my home?