Traffic Signals Essay

2238 Words5 Pages

Evolution of Traffic Signals
Introduction
Traffic signals are ubiquitous in the US and in major parts of the developed world. Without a doubt, they play an enormous role in our transportation system in maintaining road safety and alleviating congestion. Although we use traffic signals every day, few people know about their origin and the remarkable technological innovations that went into their development. This essay explores the history of traffic signals and how they have evolved through time.
Origins in Europe
Traffic signals have a very long history. Evidence shows that in the 230 B.C. of ancient Rome, milestones were used to give pedestrians directions. The first device that somewhat resembled today’s traffic signals was called a semaphore, which stood roughly 22 feet tall and had two arms—when the arms were placed at a horizontal position that signaled “stop” and when they were switched to 45 degrees that meant “move with caution.” The first semaphore was manually operated and was installed in 1868 at the intersection of George and Bridge Streets in London (Mueller, 1970; Bullock & Urbanik, 2000). Later, gas lights were added to semaphores and that allowed them to be used at night. People had high hopes for these innovative devices, but in 1872 Parliament suddenly removed all of them. There were two main reasons for their removal. First, a terrible incident of gas explosion on a semaphore happened in 1872 that injured two police officers and killed the third. The second reason was that semaphores were expensive to manufacture. Although engineers worked quickly to modify the design to make them safer and cheaper, they were not widely adopted until the rise of automobiles (Mueller, 1970).

Rise of Automobiles and … Congest...

... middle of paper ...

...traffic signals in real-time. This system could dramatically reduce on the cost of roadside sensor installation and maintenance. Some of the largest issues with this system currently are user privacy and participation (Mohan et. al, 2008).
Conclusion
Traffic signals have truly come a long way since they were first developed in Europe in the late 19th century. It is simply remarkable how traffic signals have evolved in about 100 years. They became more efficient with the introduction of automation in the 1920s and then again with the addition of microprocessors in 1970s. It is difficult to predict what the next new technology will be in the coming decades. Could it be smart phones? Or maybe machine learning? Or a combination of both? Whatever it will be, traffic signals will only become better and improve the safety and the quality of driving experience for drivers.

Open Document