“Ah, but you’re neglecting to observe that by going the speed limit the officer can also pull someone over for “impeding the flow of traffic.”
Pull over and ticket, or just pull over?
It all depends on the state and jurisdiction. The point is that there are so many vague, discretionary, and even contradictory traffic laws on the books that a cop can pretty much find a reason to pull over anyone he wants whenever he wants. And if that offense is not ticketable in itself, he can then use the stop as an opportunity to go fishing for something else that is.