In Madison, the intersection at Whitney Way and Schroeder Rd is like this 100% of the time. I used to go through it every day on my way home from work, and I'm not exaggerating. Once in awhile, I end up having to be that doofus for whatever reason, and I always feel really bad about it. If the only "go straight" lane is also the right turn lane, its fine for obvious reasons. But I think the issue is if there are dedicated left turn, straight, and a straight/right turn lanes. In these situations, I think its a jerkish thing to do to go straight from the right turn lane (at least if you had a decent opportunity to move over into the correct lane).