Last weekend I was driving from Milwaukee to Chicago with my wife. Wisconsin had recently installed new scoreboard-style highway signs that keep commuters up-to-date on current traffic conditions and at the time the message read, "Change speed to 50mph a head." I thought, "There are two heads in this car at the moment so..." and then looked over at my wife who, without waiting for me to say anything, simply said, "No." She knows me too well.