You reminded me of the biggest annoyance I have with the systems that work in stop-and-go traffic that I've tried -- they often leave too much space before they 'go' and where I live, that's just an invitation to have someone from the next lane over jump in. So the car waits too long, takes off quickly to fill the gap, and then has to brake suddenly because someone else already took that gap. You end up being yanked around, and if the driver behind you is a bit of a leadfoot can result in you getting rear ended. I've seen it happen a few times when I still commuted.