In what situation is a driver allowed to put their arm out of the window?

A driver is allowed to put their arm out of the window to give legal hand signals. Hand signals are an important method of communication on the road, particularly when indicating turns or stopping, especially for cyclists or vehicles without functioning signaling lights.

Using hand signals helps ensure that a driver is clearly communicating their intentions to other road users, which is essential for maintaining safety and awareness on the road. Legal hand signals must be done in a manner that is visible to others; this helps prevent accidents caused by misunderstandings about a driver's intentions.

Other options do not meet the criteria for appropriate situations to extend an arm out of the window. While signaling to other drivers can involve legal hand signals, not all gestures out of the window are legally recognized or safe. Expressing frustration or engaging in any type of communication that does not conform to road safety standards can lead to confusion and potentially dangerous situations on the road.