A driver with their hand out the window is typically doing what?

When a driver extends their hand out of the window, it is a common signal indicating that they are preparing to slow down or stop. This gesture helps to communicate their intention to other drivers and pedestrians, enhancing safety on the road. It becomes especially important in situations where brake lights might not be visible, such as when driving downhill or in heavy traffic conditions.

The act of signaling through hand gestures adds an extra layer of communication among road users, and it's particularly recognized as a way to alert others about a potential reduction in speed or an imminent stop. While other actions like turning left or changing lanes often involve the use of turn signals, signaling a slowdown or stop can be effectively communicated through the hand out the window, particularly when other forms of signaling might be less noticeable.