Thinking about trips versus tanks

On the way in to work today, I had to fish out cash because I didn’t have my bus pass, and I realized that with gas this high, even my extremely short trip to work starts to makes economic sense just on the gas. It’s only ~4 miles each way, but it’s all sitting at stop signs and long stop lights. Seriously, from my house to work, it’s eight stops one-way. My 14-year-old Volvo gets well under 20mpg running back and forth (in fact, it might be sub-15, which is totally embarrassing and why I don’t drive to work). I’d always looked at bus fares and figured it to be a wash, but that’s not the case at all.

At $5/gallon for the premium the 1994 Volvo 850′s owners manual tells me it needs, I’m looking at $1.25/trip over four miles, and Metro’s only $.50 more than that.

Atrios mentioned something similar today:

At $4.50 per gallon in many places I guess that changes. If you’re getting 20 mpg, a 50 mile round trip commute will cost you $11.25. The 13.2 mile trip from downtown Minneapolis to the airport, which you can do on the train for $1.50, costs 3 bucks by car.

The point I’m trying to make is that when gas was cheap, people thought in terms of the cost of filling the tank rather than the cost of making a trip. People didn’t really make a marginal cost/benefit calculation because they didn’t really perceive the cost for short trips. That’s changing.