Sorry for tilting at windmills. How 'bout this one.
We live a suburb of Dallas called Rowlett. Most places we visit go has us use Bush Turnpike, which is a toll road, to get home. As we get close to our exit off Bush, my wife will exit the highway and drive 4 extra miles to avoid the toll. I've tried to explain benefit/cost to her to no avail. Here's the math ---
1. To continue home on the toll (4 miles) costs 88 cents as we have toll tags and the cost per mile is 22 cents a mile.
2. Taking her route adds 4 extra miles + about 10 minutes of drive time as we go through several lights. If I'm calculating this correctly it costs 60 cents in gas to take this route. Her car gets 20MPG in the city @ $3 a gallon. So, 1/5 of the cost of a gallon of gas.
So, she's "saving" 28 cents to drive an extra 4 miles while adding 10 minutes to the trip. BTW, we're not Surly 1 percenters, but we can afford gas.
And, before anyone asks, I do usually drive; however, when we have the kids with us, we take her car and she prefers to drive it.