How many people know these hand signals? I didn't know the three variations. I have only signaled when making left turn, and it turns out (according to this site convention) I made the wrong signal--I used straight arm, which seems to be for right turn? But I am sure I had made my intention clear.
The only possible use for signaling for right turn for me would be if I'm riding on a bike lane that is on the left side of a street.
Has anyone needed to signal a "stop"? When would that be needed?