Final answer:
A traffic signal is a sign set on roadways to manage traffic flow and enhance safety, especially at intersections where there's excessive speeding and pedestrian safety is at risk. Installing traffic signals helps in slowing down vehicles and providing safe crossing for pedestrians, which in turn reduces accidents.
Step-by-step explanation:
The sign set on roadways like primary highways and expressways to keep traffic moving safely is a traffic signal. Traffic signals are critical for maintaining the flow of traffic and ensuring the safety of both drivers and pedestrians. In situations where many vehicles speed through an intersection without regard to the posted speed limit, a traffic signal plays a crucial role in making vehicles slow down. An example is at an intersection near a campus, where pedestrian safety is compromised because students must dodge traffic to cross the street. By installing a traffic signal, pedestrians can cross at appropriate times, reducing the risk of accidents.
Furthermore, the installation of a traffic signal is often supported by various studies and reports. For instance, a model cause-and-effect paragraph might be used to illustrate the before-and-after scenario at a specific intersection. If the number of accidents at an intersection has risen past acceptable limits, with some resulting in a loss of life, it becomes a compelling reason to install a traffic signal. Such measures are not only about controlling traffic speed but also about preventing accidents and saving lives.