Ideally, you manage to keep pedaling, and maintain your distance, without resorting to brakes or other methods. But of course it all happens, and is no big deal when it does. The key thing is being steady and maintaining a consistent (close) distance. Do that and you're golden. But if you pay attention to others, you may find that really strong/fast/smooth riders tend to never stop pedaling - they soft pedal rather than coast. One benefit is that it doesn't cause as many ripples. If you start coasting, the rider behind you probably will also, and so on and so on. It creates an unnecessary yo-yo. It's a less extreme version of yelling "slowing". Someone yells "slowing", and people slow whether they need to or not. Instant accordian. When someone yells something like that I want to yell back "STFU and just pay attention." But I don't. The only sounds I tend to make are heavy breaths, and chats with whomever is next to me. Oh, and if in front, I'll call an all-clear at an intersection.