Final answer:
A traffic signal is required for turns and lane changes, even with no traffic present, to ensure safety and order at intersections.
Step-by-step explanation:
Even with no traffic present, a traffic signal is still required for turns and lane changes. Traffic signals play a critical role in ensuring the safety of both pedestrians and drivers. They effectively manage the flow of vehicles and pedestrian traffic at intersections, preventing accidents and promoting orderly movement. Despite the absence of traffic, drivers are required to obey traffic signals, which helps maintain consistent traffic patterns and reduces the potential for collisions should another vehicle or pedestrian be unseen. A traffic signal installation is often the result of various factors, including the need to control vehicles that speed through intersections, enhance pedestrian safety, and reduce the number of traffic accidents, sometimes dramatically symbolized when a loss of life occurs due to traffic issues.