therub,
I looked at the math in depth and I believe it is slightly suspect.
First, I take issue with the 5 cents/mile depreciation - the expectation that one can buy a used car for $5k and drive it for 100,000 miles without any major repair. It may happen on occasion if you are very lucky, but on average, I think that's very unrealistic. Most cars that sell for $5k will be sufficiently old to need major maintenance at some point before the new owner gets to drive another 100,000 miles. I know many people who have bought other used cars with far higher repair costs, often adding up to much more than the purchase price after a few years. Which is why I would never buy a used car. So I think this cost is underestimated. It's likely to be far more. I think it's very disingenuous to discount major maintenance.
My Prius does 45 MPG average, not his 35MPG considered the "absolute best". With the assumed $3.50 gas price, that's 7.7 cents per mile rather than 10 cents/mile.
One may also add the hybrid battery replacement at $2200 for 100,000 miles or 2.2 cents per mile. Though part of that expense should probably be counted under major maintenance.
The Prius oil changes are every 7500 miles also, not every 5000. And I think they can be done for $20, not $25. So that's 0.26 cents per mile for oil changes rather 0.5 cent. I'm not really sure about 1 cent per 100 mile on regular maintenance. My Toyota prepaid maintenance contract for 100,000 miles costs less than 1 cent/per mile ($700 for 7 year/100,000 miles) and it includes oil changes. But there are a couple things it doesn't cover (wipers being one).
The time calculations are also wrong. 1 mile round trip, ie. 2 miles, does not take me 6 minutes on average. My 12 miles 1-way commute takes 20 minutes on average. So, 3.3 minutes per mile from home.
I used to live much closer to work - 4 miles. The 1-way commute took 13 minutes average, which is much closer to the value in the article - 6.5 minutes per mile from home.
I am also not paid hourly. My job is exempt. If I didn't currently commute 40 minutes per day, I would not be able to take a second job during those 40 minutes. There are no jobs that I know which pay for this short amount of time. Therefore, it's not really possible for me to assign a value to this commuting time.