I think that "RoShamPo" may be the Japanese name for the game. My sister taught English in Japan, and said that she saw it used all the time for decision making. In Japanese culture you pretty much have to reach consensus on basically every decision. Because winning at Rock-Paper-Scissors is pretty close to random, it's a good way to reach a conclusion without hurting anyone's feelings. School kids use it so often that it was lightning quick and just part of the flow of conversation.
I guess the next question: why was it used as the name of the route? Scissors has a FA date of '91, and Ro went up in '92, so there's sort of a progression. Jamie Baker and Jim Link are listed as the FAs - anyone know why they used an Asian name for Rock-Paper-Scissors?