Here is a question I received and answered on the now-defunct website AllExperts.com:
I am 35 and have been driving for nearly 20 years and so don’t remember my driver’s test. It was brought to my attention today that there are hand signals people are supposed to know if ever there signals don’t work? Honestly never had that issue as I take care of my vehicle and don’t remember that on driver’s test either. That’s an actual thing? I mean if someone was waving an arm out the window like a crazy person I would make a point to let them do whatever they want.
Yes, hand signals are real. The automobile predates electronic turn signals by nearly 50 years, so during that time hand signals were very common. They continue to be used by motorcyclists and bicyclists to this day, so it is important to know them. Here is an easy guide to common hand signals: