Warning! Mom, you won’t like this one!
Most men cannot resist the challenge of trying to hit the target when peeing on a moving bus or train. It must be the same impulse that gives rise to the popularity of archery, riflery and darts. But the challenge is greater on a moving vehicle because the necessary balance requires the additional skills of surfing or snowboarding. The combination of required skills thus makes bus/train peeing quite similar to the Winter Olympic Biathalon (riflery on cross-country skis). Of course novices can hang on to the wall handles that are usually provided or even sit down. But world class performers will stand with no hands. For non-participants, it is advisable to use the restroom early in your journey.