Since starting my longer commute I have noticed the biggest bug bear for me is the number of vehicles that do not signal at roundabouts. I have quite a few roundabouts, both mini and large ones. It is often very hard to know ones intentions on the roundabout as I approach so have to slow until they make there intentions clear. If they used there indicators in most cases I would be able to go through the round about without slowing. I don’t remember this being much of an issue 10 / 15 years ago when I was cycling much greater distances.