"rotaries" here in the US are pretty tricky and I ride one on a busy highway sometimes. I usually get my timing correct but the last time I messed up and was lucky no one got mad or yelled at me. I usually get into the rotary when there is a lull in the traffic and stay to the right but hold my lane as best I can until I exit 1/3 the way around. I have to pass one incoming lane on my right and they usually see my strobe and slow for me with no trouble. the last time I went into the rotary prematurely causing the speeding traffic to slow just for me, and someone who wanted to exit really had to slow so I could get out of their way, then the entering traffic on my right was quite brisk and really had to slow to accomodate me. after I exited I felt a bit embarrassed that I had not handled it better that day. when I tell local people that I ride through that rotary/intersection they give me the "u r nutz" stare.