In which situation is it critical for traffic control personnel to wear high-visibility clothing?

Wearing high-visibility clothing is essential for traffic control personnel in any situation where they are near moving traffic. This type of clothing, often brightly colored and featuring reflective materials, serves a vital purpose: it allows personnel to be seen by drivers, especially in conditions where visibility may be compromised, such as low light or inclement weather. The heightened visibility helps to ensure that drivers are aware of their presence, which significantly reduces the risk of accidents and enhances the overall safety of both the workers and the motorists.

In contexts where traffic is present, the chances of a worker being overlooked can increase, making high-visibility clothing an indispensable part of their safety gear. This applies regardless of other conditions, such as the weather or whether machinery is being operated, since the primary concern is being seen by moving vehicles. Therefore, the correct answer emphasizes the importance of visibility when near traffic, making it a critical safety standard in traffic control situations.