Trafficators are

semaphore signals Railway semaphore signal is one of the earliest forms of fixed railway signals. This semaphore system involves signals that display their different indications to train drivers by changing the angle of inclination of a pivoted 'arm'. Semaphore ...

which, when operated, protrude from the bodywork of a

motor vehicle A motor vehicle, also known as motorized vehicle or automotive vehicle, is a self-propelled land vehicle, commonly wheeled, that does not operate on rails (such as trains or trams) and is used for the transportation of people or cargo. The ...

to indicate its intention to turn in the direction indicated by the pointing signal. Trafficators are often located at the door

pillar A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member ...

History

They first appeared in the 1900s, when they were actuated either mechanically or pneumatically. In 1908, Alfredo Barrachini in

Rome , established_title = Founded , established_date = 753 BC , founder = King Romulus ( legendary) , image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, Italy).svg , map_caption ...

added electric lights inside the arms that turned on as they extended, but operation was still by a cable system. Electric operation came in 1918 when the Naillik Motor Signal Company of

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added electric motor drive. This system was superseded by two

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inventors, Gustave Deneef and Maurice Boisson, who used a linear

solenoid upright=1.20, An illustration of a solenoid upright=1.20, Magnetic field created by a seven-loop solenoid (cross-sectional view) described using field lines A solenoid () is a type of electromagnet formed by a helix, helical coil of wire whose ...

in 1923. The final complete system came in 1927 when

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-based Max Ruhl and Ernst Neuman combined internal illumination and solenoid operation: (but see

Gladstone Adams Captain Gladstone Adams (16 May 1880 – 26 July 1966) was a professional photographer and chairman of Whitley Bay Urban District Council, and is one of several people claimed to have invented the windscreen wiper (known in the United States as th ...

). The shape of the trafficator arm is closely based upon the shape of the semaphore signal arm used by the Royal Bavarian Railway beginning in 1890. The only difference from the railway arm is that it is halved down its length so as to fit flush with the vehicle's exterior. They were common on vehicles until the introduction of the flashing amber, red or white

indicators Indicator may refer to: Biology * Environmental indicator of environmental health (pressures, conditions and responses) * Ecological indicator of ecosystem health (ecological processes) * Health indicator, which is used to describe the health ...

at or near the corners of the vehicle (and often along the sides as well). They have been increasingly rare since the 1950s, as ever-stricter legislation has prescribed the need for the modern type of flashing signal. Many historic vehicles (e.g. pre-1960

Volkswagen Beetle The Volkswagen Beetle—officially the Volkswagen Type 1, informally in German (meaning "beetle"), in parts of the English-speaking world the Bug, and known by many other nicknames in other languages—is a two-door, rear-engine economy car, ...

) that are used on today's roads have had their trafficators supplemented or replaced with modern indicators to aid visibility and to meet legislative requirements. In some countries trafficators may now be retro-fitted with flashing lights.

References

* ''The Motor Car: Its Evolution and Engineering Development''. John Day. Bosch Ltd., 1975. .

External links

* {{CarDesign nav Auto parts German inventions