The program flashing lightIt was on windows, hidden in door pillars, on the front fenders, the side fenders, bare behind a piece of orange plastic, drowned in an excess of chrome, integrated into headlight and taillight units, captured in the side mirrors, and even as a dot of light on the roof edge. From a mechanical red sign to a fully integrated design element in the modern cars of today. Once, in the beginning, it didn't even blink!

Nowadays, there are quite a few motorists who do not seem to know that their car is equipped with turn signals that allow them to signal their intentions to fellow road users. They are either not used at all or, for example when entering the motorway, are switched on indiscriminately before the merging lane is reached, meaning that as a fellow road user you still do not know when the merging is about to take place. The turn signal is therefore an important and very useful, but unfortunately sometimes neglected or misused, instrument in our vehicles.

Yet there was a time when people drove around without turn signals and had to indicate their plans by using hand signals out the window. To turn left, you stuck your left arm straight out the window parallel to the ground; to turn right, you rested your elbow on the window and raised your forearm with an open hand. If you wanted to stop, you stuck your left arm out parallel to the road and made a fishing motion downwards. Nowadays, when driving a very old car, you still have to apply these hand signals where necessary. These were the rules in sunshine as well as in the rain. So, a wet left arm was quite a possibility when you went out in the car back then.

Surely there had to be a safer and more comfortable way? In 1907, Percy Douglas-Hamilton filed a patent application for a device 'indicating the intended movements of vehicles'. These were lights in the shape of hands, so that other drivers, accustomed to reading hand signals, would easily understand the meaning. In 1914, a woman devised a mechanical signaling arm; she was also the first to come up with a mechanically operated brake signal for the rear of the car.

When the driver pressed a button, a small sign appeared on the rear bumper indicating which direction the driver should turn. The first flashing turn signals appeared in 1920. As with so many inventions, the brands were not interested in the beginning, and the first patents for turn signals quietly expired, leaving us, for the time being, with mechanical signaling using extending arms.

1 tail light for left, right, braking and stopping.

Mechanical arm as a 'flashing light'

In Europe, mechanical arms that folded out horizontally became commonplace. These were powered by electromagnets to activate an arm usually mounted high on the door pillar. As soon as these arms were extended and thus in the active position, power flowed to them and the lights illuminated. When folding in, these turn signals folded into the door pillar, the power was cut off, and so the light went out. This allowed drivers to keep their hands on the wheel, which was safer and resulted in fewer sweaty left sleeves. Ford did not offer these mechanical turn signals on cars made in the US, but they were installed on European models built at the factory in Germany. Scintilla, a Swiss firm, manufactured these mechanical turn signals, where the driver used a switch in the center of the dashboard to activate the arms.

Mechanical turn signal on the windshield.

There was also a Brit who suggested the idea of ​​using different colored lights, just like traffic lights, but this system proved to be far too complicated for moving vehicles.

The type of mechanical turn signal was used for a long time, and there are several 'inventors' of this system. In 1908, the Italian Alfredo Barrachini added electric lighting to a cable-activated system. In 1918, the Naillik Motor Signal Company of Boston introduced an electric motor. To slow down or stop, a switch in the brake pedal was activated, causing the mechanical arms on both sides of the car to extend. Separate switches could be operated for left or right. At night, the small hands were illuminated as standard. Thus, multiple people experimented with vehicle signaling in various ways. As more modern turn signals were introduced, mechanical turn signals were phased out, primarily because the extendable versions were fragile, often broke, and tended to get stuck in the door pillars.

mechanical turn signal on

mechanical turn signal off

Buick introduces the first modern turn signal

In the United States, it was the brand in 1923. Buick that becomes the first American automaker to introduce factory-installed flashing turn signals. In 1939, it was marketed as a new safety measure, operated by means of a switch.

These flashing signals were only active on the taillights. In 1940, Buick improved the turn signals by extending the signals to the headlights and adding a self-cancelling mechanism. That year, directional signals became standard on Buick, Cadillac, LaSalle, and Hudson Country Club vehicles, and optional on Chevrolet, Oldsmobile, Pontiac, Hudson, and Packard models for about $10. In 1941, Dodge offered turn signals as an option on all models.

Why does a turn signal make a sound?

The inventor of the flashing light as we know it today is Joseph Bell. With his invention, he passed current through a system containing a spring made of two different types of metal. When heated by electricity, this spring moved because one metal expanded faster than the other. Due to the movement of this spring, the electrical circuit was closed and then interrupted at regular intervals.

As a result, the light at the end of the line would turn on or off. Bell practically placed this spring behind the dashboard, close to the driver. After all, there were already lights on the dashboard—close to this system—that served as an extra safety feature to indicate that the turn signals on the outside of the car were flashing. The driver could hear the spring snapping inside the dashboard, producing a rhythmic click at the same pace as the flashing of the turn signals.

So, actually, it wasn't a conscious choice by Bell to make the turn signal produce a sound, but rather it was due to the mechanical application. By now, we have become so accustomed to this that turn signals still make this sound, even though Bell's mechanical solution with the spring has long been replaced by a chip that is, of course, silent. Nowadays, the sound is therefore added.

After the Second World War

After World War II, turn signals were fitted to almost all cars, with indicator levers mounted on the left side of the steering column. Nowadays, turn signals are mandatory for vehicles using public roads, unless they are antique vehicles that are not equipped with turn signals. Some owners of such cars install aftermarket turn signals, but this is often not done because the classic car would then no longer be authentic.

tail lights classic Chevy.

The 1960s brought other innovations in signal switching. Ford planned to install repeating turn signals on the rear of the 1964 Ford Thunderbird, but this was delayed for a year because it was unclear whether it was legal. In 1965, however, this did go ahead, and they were factory-fitted on Thunderbirds, soon followed by Mercury Cougars (1968-1970), Shelby Mustangs (1968-1970), and the 1969 Chrysler Imperials. 1968 marked another change: Federal Motor Vehicle Safety Standard 108 required orange instead of white turn signals at the front, while at the rear, these could be red or orange. Warning lights where all four turn signals flash simultaneously were also made mandatory.
 
In the 1980s, reliable light-emitting diode (LED) technology entered the market. These lamps do not depend on the glass in front of them for their color, because the light itself already has that color. The incandescent lamp is losing ground in all areas.

With approved technology from Audi and VW, there is now the three-flash turn signal. When you activate a turn signal, it automatically flashes three times and then automatically switches off. If you need them longer, you have to override this yourself. This feature is designed to ensure that turn signals do not remain on unnecessarily, which can cause frustration and confusion among other drivers. It appears that the French will demonstrate en masse if this is implemented on French cars, as the French prefer to simply keep their turn signals on during a full overtaking maneuver.

New techniques also create new design possibilities.

Although turn signal technology has fundamentally changed little in recent years, minor adjustments will undoubtedly still take place in the future regarding application, safety, and material usage in relation to the turn signal.