What is the proper hand signal to indicate that you need to stop?

The proper hand signal to indicate that you need to stop is to point your arm downward. This signaling method is widely recognized and serves as a clear communication to other drivers and pedestrians that you intend to halt your vehicle. Extending your arm downwards signifies a definitive stop, making it easily noticeable to others around you.

In contrast, pointing upward typically indicates a right turn or may signal a lane change, while a straight left arm is used to indicate a left turn. Waving the hand may be interpreted as a greeting or may not provide a specific instruction regarding your driving intentions. Therefore, pointing downward is the most appropriate and universally accepted signal for stopping, ensuring clear and effective communication while driving.