• cars
  • The AAA releases a yearly report titled "Your Driving Costs" that summarizes the per-mile costs of driving. It's nicely detailed, giving summaries for large/medium/small vehicles, and averages for 10k/15k/20k miles per year.
  • the IRS allows business mileage to be deducted (included are: depreciation, lease payments, maintenance/repairs, gasoline, oil, insurance, or vehicle registration)
  • various carsharing organizations bundle all costs into their rates (insurance, gas, etc). However, they usually charge per hour rather than per mile, making it more difficult to use their rates to compare.
  • more
• bicycle
  • 9.6¢ per mile (see "Total User Costs" — I prefer to compare costs without including externalities)

personal comparisons

• May 2010, commuting from Chicago to Arlington Heights, IL
  • via a WRX (the route is 15k miles a year)
    • $692 per month (including all costs listed on the AAA publication)
    • $401 per month (including all costs except for depreciation)
  • via Metra + 6 miles of biking each way: $141 per month

related websites

• CommuteSolutions.com's True Cost of Driving