Quote Originally Posted by Burney View Post
It's not actually etiquette, though, is it? Indicating is actually road safety and basic driving competence. If you don't indicate when turning, you are an unsafe and incompetent driver. What is more, you are almost certainly likely to be in breach of the law.
It depends though, doesn't it? Changing lane without indicating? Dangerous, less so if you always check it is safe first. Not indicating on a roundabout? Less so as all you're really doing is inconveniencing the person entering.

I would put the latter in the 'in breach of the law and mildly irritating but not dangerous' category. Like speeding.