What is an essential feature for traffic control in low-light situations?

Answer: C — Reflective materials and lighting

An essential feature for traffic control in low-light situations is reflective materials and lighting. These components play a crucial role in enhancing visibility during times when natural light is limited, such as at dusk, dawn, or during inclement weather. Reflective materials, such as tape or paints, ensure that objects are visible to drivers and pedestrians by reflecting headlights, which can significantly reduce the risk of accidents in work zones. Additionally, proper lighting, such as portable lights or illuminated signs, helps to clearly define the traffic control measures in place, ensuring that all road users can navigate the area safely. While other options may be useful in certain contexts, they do not address the unique challenges presented by low-light conditions to the same extent. Traffic cones provide some visual guidance, but they may not be effective without additional visibility features. Personal flags can aid in directing traffic, but again, their efficacy diminishes in poor lighting without reflective or illuminated enhancements. Sound signals, while helpful in some traffic situations, do not provide visual cues that are critical in low-light environments. Thus, the combination of reflective materials and lighting is key to maintaining safety and clarity during nighttime or low-visibility conditions in work zones.