The traffic light is an artifact found in busy pedestrian and vehicular traffic routes, whose main objective is to regulate the passage of these. It was designed with the purpose of assuring drivers and the greatest possible safety, while they made use of the street; This is due to the increase in the purchase of automobiles at the beginning of the 20th century, due to the accessibility and low price that these had. This term comes from the Greek word “σῆμαφόρος”, which means “the one who bears the signs”.
Before, in Spanish, the series of towers that used flags and lights to transmit important information were known as semaphores; Likewise, the optical telegraphic stations that warned of the movements of the vessels, in addition to significant news, were also called traffic lights. However, the device as it is known today was not devised until 1868, by John Peake Knight, who installed it in the city of London, in a railway station.
In 1910 the machine was automated, providing more security to the traffic police who controlled the passage. Its development came over the years, but passersby could not adapt to the meaning of the lights and most of the time, accidents occurred due to this desynchronization. For this reason, the yellow light was installed, which was in charge of warning the driver of the change from green light (free passage for drivers) to red (passage of people on the streets), facilitating much of the process.
Some engineers referred to pedestrians as "an obstacle to the regularization of traffic", a fact that caused concern, in the legal field, by the importance that was being given to the lives of all street users alike. Today, there are various types of traffic lights, such as conventional, pedestrian, rail and specialized (for public transport, with the option of change and for cyclists). Likewise, the use of led lights has begun, due to the lower amount of energy they use, low risk of emitting some type of pollutant and the minimum maintenance they entail.
