Since the advent of motorized vehicles, manufacturers have put a lot of thought into making sure drivers can communicate crucial information to one another. Whether you're driving a car, truck, or ...

A complete guide to volleyball referee hand signals, from ball in/out to misconduct cards, based on official FIVB and USA ...

Doubles players can use a variety of hand signals to communicate with their playing partner during matches. Before a serve, the net player on the serving side can indicate to the server how they ...

Turn signals are one of the earliest automotive safety features. In the early 1900s, some cars came with mechanical arm "trafficators" that would pop out of either side of the car to indicate a turn.