Things like this are cool. What I would be curious to see though, rather than setting global parameters (i.e., politeness), would be to have each agent have its own politeness score (as well as other attributes). Models like the one linked to here work as if each agent is a particle, rather than autonomous decision-maker adapting to their circumstances locked in long-term, iterated games with other anonymous drivers.

This way, agents would adapt their attributes to maximize their own local advantage, and therefore could see how large scale trends develop. I've driven in many countries and regions within countries, and it's just wild how "driving cultures" vary so much. Some places the drivers are so polite to the point it really makes things dangerous, other places the drivers are vindictive (distinct from being aggressive driver). It would be interesting to model how driving cultures emerge.

Edit: I guess the short story is I'm really curious why some places, like Bangkok driving is chaotic, dangerous, gridlocked, and no one adheres to traffic laws much or yields to pedestrians, but relatively devoid of road rage (and people will let you merge over if you need to). In DC, people carefully adhere to red lights, stop signs, pedestrians, etc but will go far, far out of their way to block you from changing lanes once they see your turn signal go on.

Also, exploring the game theoretic (probably prisoner's dilemma?) aspects of tailgating and how that seriously depends on the driving culture. When someone tailgates, the tailgatee can slow down (everyone loses), speed up or move out of the way (tailgater wins/tailgatee loses), etc. If everyone slowed down when tailgated, there would be no benefit of tailgating; if enough people give in when tailgated, that keeps rewarding the behavior. Anyway, that would be something fun to explore in one of these traffic simulations.