What is the purpose of a traffic signal?

Answer: B — To control the flow of traffic

The primary role of a traffic signal is to control the flow of traffic at intersections, ensuring that vehicles and pedestrians can navigate safely and efficiently. By regulating when vehicles should stop and go, traffic signals help prevent accidents and reduce congestion. They assign right-of-way, typically using a system of red, yellow, and green lights, guiding drivers when to yield and proceed. In addition to this core function, traffic signals can also enhance pedestrian safety by allowing designated crossing times, which further emphasizes their role in managing traffic dynamics at busy junctions. While traffic signals can sometimes convey additional information, such as directional indicators, their main and most critical purpose is fundamentally to control traffic flow.