I was just thinking about interactions like this I've had a few times with different nice drivers, where I think they'll be trying to wave me through (no flashing brights or anything), I'm assuming to be nice, but they're far enough away that I can't see them, so I'm not entirely certain of their intent. Usually it's a busy road, so there's very little margin for error, if I misjudge what they're doing, then there's gonna be a problem. And then you both end up missing a chance to go because they screwed up the process, when, if they just hadn't tried to be nice and just went like they were supposed to, we both could've gone. Just follow the dumb traffic laws.

The exception to this though is at my kid's school. To turn into the school, there's a system that most of the parents follow and it works well, we essentially treat the entryway as a modified 3-way stop. Whoever has the easiest time to get in/get out go last in the order. So people needing to pull out and make a left turn onto the main road get first priority, then people needing to make a left turn into the school, finally people making a right-hand turn either into or out of the school go last. Anyone not going into the school just keeps going.

This system works better than when a traffic cop is occasionally posted to direct traffic (for whatever reason). With the cop, traffic gets backed up everywhere around the school and it takes everyone forever to get where they need to go. Without the cop, most people follow "the system" and traffic flows smoothly. When someone doesn't follow the system, it's not necessarily a surprise because they just don't wait, but usually a car or two later follows the system and everyone goes where they need to. You're rarely waiting for long.