Ah no, they don't reverse and stop, they just continue driving like nothing happened. UPDATE: I did some further testing; traffic spawned, and cars spawned personally then controlled via the Traffic app seems to work properly; they stop when hit, but there are some cars that reverse before stopping (which also seems to reverse more when it's displaced/hit again) and the occasional car driving off with hazards. Cars spawned personally and setting the AI to "traffic" do not work, they're the ones that always drive off on crashes. Also, the u-turn mechanic works weirdly and the cars usually end up hitting something and damaging themselves. Would an option to disable this be possible?