Trafficators are semaphore signals which, when operated, protrude from the bodywork of a

motor vehicle A motor vehicle, also known as a motorized vehicle, automotive vehicle, automobile, or road vehicle, is a self-propelled land vehicle, commonly wheeled, that does not operate on railway track, rails (such as trains or trams), does not fly (such ...

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

History

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

Rome Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...

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

Boston Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeas ...

added electric motor drive. This system was superseded by two French inventors, Gustave Deneef and Maurice Boisson, who used a linear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 whos ...

in 1923. The final complete system came in 1927 when

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

-based Max Ruhl and Ernst Neuman combined internal illumination and solenoid operation: (but see Gladstone Adams). The shape of the trafficator arm is closely based upon the shape of the semaphore signal arm used by the Royal Bavarian State Railways beginning in 1890. The shape differs in that the trafficator has only the lower 'blade' of the rail signal's terminal 'arrowhead', so that the retracted trafficator sits 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), now referred to as "turn-signals". 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, is a small family car produced by the German company Volkswagen from 1938 to 2003. One of the most iconic cars in automotive history, the Beetle is noted for its distinctive shape. Its pr ...

) 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 Semaphore