Not sure where you are, but in the US, the rule is to stay right in the first place. Not get over once someone is coming. This avoids all the problems you menti

Not sure where you are, but in the US, the rule is to stay right in the first place. Not get over once someone is coming. This avoids all the problems you mention. It's just that people don't do it, and have little incentive to. Part of what I'm suggesting is that you should have to be ultra cautious anytime you're in the passing lane. Which is an incentive to quickly get out of it.