How Turn Signals Have Evolved

Written by Chloe Harwood

At the start of the 1900s, drivers signaled to pedestrians and other drivers their intention to turn (or stop) their vehicles with their hands.  Turn signals didn’t exist back then.  The hand signal conventions for right and left turns and stop have not changed since that time and are still commonly used by vehicles with turn signals. Though the basic turn signal technology has not changed in years, future improvements may include increased strength and durability for components that are consistently used, an alert when the turn signal switches off even before we have started our turn, and customizable turn-signal tones. Read on to learn more about the evolution of turn signals! And, thank you to the Sales team at East Hills Chevrolet for providing us with this information we’re about to share with you!

The first modern turn electric signal can be attributed to Edgar A. Walz, Jr. who, in the early 1920s, obtained a patent for one and attempted to market it to major car manufacturers. Believe it or not they just were not interested and the patent expired fourteen years later.

However, Europe’s turn signal situation started differently. The solution for signaling turns was originally solved with hand signals but later via semaphore indicators, which are mechanical arms known as “Trafficators” mounted on vehicles. The trafficators were powered by electro magnets that raised an arm (mounted high on the door pillar) indicating a turn was about to be made. Once the arms were in the “on” position, power went to the lens area to light a small bulb. The trafficators folded into the door pillar when they were “off.”

Buick was the first U.S. automaker to offer factory-installed flashing turn signals in 1939. These turn signals were advertised as the “Flash-Way Directional Signal” and they worked for the rear lights only.  In 1940 Buick improved the directional indicators by adding a self-canceling mechanism, as well as extending the signals to the front lights. In 1940, directional signals became standard on Buick, Cadillac, LaSalle, and Hudson vehicles and optional on Chevrolet, Oldsmobile, and Pontiac for a $7.95 fee.

For vehicles without them, the Illinois-based Lester Company offered a Simplex Direction Signal Kit for Do-It-Yourselfers advertising their $8.95 signals would function “like factory-installed models on expensive cars”.  

The Sixties brought other changes to turn signals. Initial plans called for Ford to put sequential rear turn signals on the 1964 Thunderbird, however, installation was postponed a year while legislatures across the United States considered whether to make the rear turn signals legal.  1968 marked another change: Federal Motor Vehicle Safety Standard 108 required amber (rather than the white) lens front turn signals; rear signals could be either amber or red. Note: It was also in the 1960s that four-way hazard flashers were first required.

Signal light reliable light-emitting diode (LED) technology was introduced in the 1980s. Because such lights don’t depend on lens color, they emit true amber and red hues. While it hasn’t happened yet, it may not be long before filament bulbs have been 100% phased out.


About the author

Chloe Harwood