What is the primary purpose of traffic signals?

Answer: B — To manage the flow of traffic

The primary purpose of traffic signals is to manage the flow of traffic. Traffic signals play a crucial role in regulating how vehicles and pedestrians interact at intersections and pedestrian crossings. By providing visual cues that indicate when to stop, proceed, or yield, traffic signals help to ensure that vehicles move in an orderly fashion, reduce potential accidents, and improve overall traffic efficiency. Controlling vehicle speed, while important, is not the main function of traffic signals; they inherently do not dictate speed limits, although they can influence driver behavior. Ensuring that all vehicles stop is also not the main aim, as many signals allow for the safe movement of vehicles when it's appropriate. Moreover, traffic signals are not designed for identifying road construction areas, which is instead managed through signs and other forms of traffic control. Thus, the focus on managing traffic flow highlights the essential role that traffic signals play in maintaining order and safety on the roads.