The Evolution of Traffic Lights: From Creators to Modern Systems

Introduction

The invention of traffic lights was a significant milestone in the history of urban infrastructure. These devices have evolved from simple two-colored signals to sophisticated systems that control traffic flow and ensure road safety. This article traces the origins of traffic lights, focusing on the inventions of J.P. Knight, Garrett Morgan, and other key figures who contributed to their development.

The Invention by J.P. Knight (1868)

The first traffic light was invented by J.P. Knight, a British railway signaling engineer. The device was installed outside the Houses of Parliament in 1868. It was a elaborate setup, resembling railway signals of the time, with semaphore arms and red-green gas-lit lamps. The system was designed to control traffic at the intersection of Great George Street and Bridge Street in Westminster, London.

Unfortunately, the early device proved to be somewhat imperfect. It exploded in an accident, resulting in the death of a policeman. This tragic event discouraged further development of traffic signals until the rise of the internal combustion engine led to an increased need for improved traffic control systems.

The Rise of Electric Traffic Lights (1912)

The modern electric traffic light as we know it today was developed much later. The first working electric traffic signal was installed in 1912 in Salt Lake City, Utah, by police officer Lester Wire. His invention marked a significant advancement from the gas-lit systems of the past.

Garrett Morgan and the Modern Three-Color System (1923)

Garrett Morgan, an African American inventor, registered his design for a three-color traffic signal in 1923. This system included red, green, and yellow lights, which became the standard for controlling traffic. Morgan's invention was a crucial step in the evolution of traffic lights, reflecting the growing demand for more efficient and reliable traffic management.

Standardization and Widespread Adoption

The standardization of traffic lights continued to evolve in the coming years. In 1914, red-green systems were installed in Cleveland, setting a precedent for future installations. Three-color signals operated by police officers from a tower were first implemented in New York in 1918. In London, the first traffic lights appeared in 1925, operated manually by policemen using switches.

Advancements in technology further improved traffic lights, leading to the introduction of automatic signals in 1926 in Wolverhampton. These automatic systems worked on a time interval, significantly enhancing traffic management. The first vehicle-actuated signals appeared in 1932 on the junction between Gracechurch Street and Cornhill in the City of London.

By the 1930s, peculiar traffic signals were still in use. For instance, Fifth Avenue in New York had elegant gilded columns decorated with statuettes, and Los Angeles traffic lights would even ring bells and wave semaphore arms to awaken sleepy motorists. However, standardization soon became the norm, with red-amber-green signals becoming the universally adopted standard.

Conclusion

The history of traffic lights is a testament to human ingenuity and the continuous quest for safer and more efficient road management. From the early gas-lit signals of J.P. Knight to the modern three-color systems pioneered by Garrett Morgan, these devices have played a vital role in shaping urban environments and ensuring the smooth flow of traffic.