My wife and I have become a one-car couple. The main thing that has made that feasible for us is KAT. At various times, she drives me to the bus stop (5-minute trip), so she can have the car for the day for errands, shopping, doctor appointments (both hers and her mother's), etc.
Instead of dealing with rush-hour traffic for 25 minutes, I can "leave the driving to" KAT and get in some good reading during the commute.
In short, "smart tripping" has allowed me to eliminate one of our cars, reduce commuting costs, help the environment, reduce the hassle of commuting, and increase my reading time!