Traffic lights help us stay safe by telling us when we can cross the street. Many traffic lights are signals for drivers and pedestrians alike. Ever since more and more people moved into cities, inventors have worked to reduce the number of traffic accidents.
Traffic signals work on a simple premise: tell people when it is safe to go. The earliest traffic signals used two signals (Stop and Go). The challenge with these signals was that they did not give people time to react. In 1923, Garrett Morgan patented a traffic signal that incorporated three settings. Morgan’s traffic signal included an intermediate setting that stopped all traffic. In Morgan’s design, arms of a T-shaped design folded down to stop traffic in both directions.
When we think of traffic lights, we think of three lights stacked on top of each other. This design came later and uses a design patent. The US Patent and Trademark Office awards design patents when an inventor wants to propose changes to an invention’s appearance. If you see a patent number with the letter ”D” at the beginning, it is a design patent.
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