Stoplights, also known as traffic lights or signal lights, are one of the most common safety devices used on roads to control the flow of traffic. They are used to regulate the movement of vehicles by providing a visual indication, such as a red light for stopping, yellow for caution, and green for go. Other synonymous words used for stoplights include traffic signals, streetlights, semaphore signals, traffic control lights, and signal heads. Regardless of what they are called, these devices play a crucial role in ensuring safety on the road by preventing accidents and reducing traffic congestion. Remember to always adhere to the signals displayed and drive with care.