How should you signal your intention to slow or stop with a hand signal?

To communicate your intention to slow down or stop while driving using hand signals, the correct method is to extend your left arm down to the left. This position clearly indicates to other drivers that you are about to reduce your speed or come to a stop. Using a straight down position for your arm provides a clear visual cue and is universally recognized by motorists, making it a safe choice for signaling.

Other methods like extending your arm straight out or upward serve different purposes; for instance, a straight-out arm indicates a left turn, while an upward position signals a right turn. Waving your arm wildly is not a recognized hand signal which can lead to confusion among other road users about your intentions. Thus, using the correct hand signal is crucial for ensuring safe communication on the road.