There's some single-lane Swiss mountain roads, with occasional passing spots. There's a specific rule in the Swiss driving code that the car going up has priori

There's some single-lane Swiss mountain roads, with occasional passing spots. There's a specific rule in the Swiss driving code that the car going up has priority, so the car driving down gets to reverse to the closest passing spot - presumably reversing upwards is less scary, as guardrails may or may not be present... But then there's the extra rule that on some roads if you meet a "car postal" (bus service run by the Post Office) it gets to decide what you do :)