When Were Turn Signals Added to Cars? | The Full History

When were turn signals added to cars isn’t a question with a single year, and the answer depends on whether you mean the first patent, the first factory-installed option, or the first federal requirement. The 1939 Buick is the milestone most people remember, but the story stretches back decades earlier.

Early Turn-Signal Patents and Devices

The earliest turn-signal concepts date to the 1900s, before electric lights were common on cars. A mechanical turn-signal device was patented in 1907, and illuminated signaling systems appeared as early as 1909. These early devices were often mechanical flags, hands, or illuminated arms mounted to the car’s body rather than flashing bulbs.

Edgar A. Walz Jr. patented a modern electric turn signal in 1925 (patent US1555513A), and Oscar J. Simler’s automobile turn signal was patented in 1929. Several other experimental designs followed, but none became standard equipment.

What Drivers Used Before Electric Signals

Before turn signals existed, drivers used hand and arm signals from the window. This system worked but had obvious limits in bad weather, at night, and on wide roads where the driver behind couldn’t see the gesture clearly. The Smithsonian’s collection includes early mechanical signaling devices that attempted to solve these problems, but they never caught on widely.

The First Factory-Installed Turn Signals

The first factory-installed electric turn signals on a production car are commonly credited to the 1939 Buick, sold in the U.S. as the “Flash-Way Directional Signal” option. Buick offered these flashing directional signals on its Buick Eights, and sources describe it as the first U.S. automaker to do so. By 1940, Buick extended the signals to the front lights and added a self-canceling mechanism.

A point of nuance: the Talbot 105 may have been the first car with factory-installed illuminated turn signals, dating to roughly 1932–1935. The Talbot 75 and Talbot 95 also appear in some accounts. Different sources credit different manufacturers, which is why saying a single car “invented” turn signals is misleading. The distinction matters between early patents, experimental devices, and the first factory-installed production-car system. The Buick 1939 is the correct answer for the first U.S. mass-market production-car offering.

When Did Turn Signals Become Standard?

Turn signals were not common on most cars until the early 1950s. A decade would pass before they became standard equipment rather than an optional extra. In the U.S., turn-signal requirements were later incorporated into federal vehicle lighting standards, with 1968 often cited as the year front and rear turn signals became required on new vehicles.

For a buyer looking to upgrade an older vehicle or replace worn-out signals, modern LED options are a solid choice — our tested roundup of the best turn signals for cars compares the top models for visibility and durability.

Why the History Matters

The evolution from hand signals to mechanical flags to flashing electric lights took roughly 60 years. Each step solved a real problem: visibility, reliability, and finally standardization. The 1968 federal requirements closed the gap, but the engineering story began with those early 1900s patents and reached its first production milestone with the 1939 Buick.

The Smithsonian’s collection documents early turn-signal devices that predate flashing electric lights, showing how far the technology traveled before it became the ubiquitous safety feature drivers use today.