A DOT study indicates that 50% of trips are three miles or less
My car normally gets 25-30mpg, but on a three mile trip, it averages 10mpg because it never warms up. So, if my math is right, I break-even on the cost of a commuter if I eliminate about 300 short trips... That sounds like a lot until I realize that I have two grocery stores, 4 drug stores, 1 Target, 1 K-Mart, 1 post office, 1 mall, at least 16 fast foods, 3 bookstores, 3 Starbucks, and 1 COLDSTONE within an easy three mile radius of my house...so it's less than 1/day for a year.