I’ve actually sat in traffic before thinking about why things are annoyingly stop-and-go. There’s normally no reason for it, if all of the cars can fit on the road all of the cars should be able to go 60 miles per hour together (though i suppose depending on indivitual driving skill that may not be all that safe.) Traffic can be thought of as fluid and stop-and-go traffice as pressure waves in that fluid. According to this article even a single persson smoothing out the waves can help to aleviate the stop-and-go, if not speed things up overall. I’ve tried it before it at least helps me pass the time playing around in traffic, I don’t think i’ve ever been in traffic bad enough to really test out the theory (I do my best to avoid it.) Interesting read though.