Factory-installed electric turn signals first appeared on the 1939 Buick and were called the Flash-Way Directional turn signals. The turn signals were marketed as a safety feature and indicated the turning direction using the vehicle's rear lights.
Prior to 1939, several individuals patented designs for turning signals, but car manufacturers showed no interest. In Europe signaling arms, known as trafficators, were standard on German-built Model A's. These signaling arms raised and lit a small bulb to indicate the driver's turning direction. The trafficators underwent many updates between the early 1900s and the invention of modern turn signals in the late 1930s but were ultimately phased out due to their fragile nature.