Well, the same can happen to motorcycle riders. And there's a hand signal for that, too. In order to let someone know that their turn signal is still on, a rider will extend their left arm outward ...

Motorcyclists use a number of hand gestures to communicate with others while driving for safety. Here's what one of those ...

State driving laws contain provisions for hand signals that apply not only to motorcycle riders ... simply extend your left arm and hand horizontally. The hand signal for making a right turn ...