When should retroreflective materials be used in work zones?

Retroreflective materials play a crucial role in enhancing visibility in work zones, particularly during periods when natural light is insufficient. The correct answer highlights the importance of utilizing these materials when visibility is expected to be low, such as at night or in poor weather conditions.

In low visibility situations, retroreflective materials significantly improve the ability of drivers to see signs, cones, barriers, and other crucial traffic control devices. This creates safer conditions for both workers and drivers by providing clearer guidance and warnings. It's essential to ensure that these materials are in place during nighttime operations or adverse weather scenarios, as this maximizes their effectiveness in alerting motorists to potential hazards.

The other scenarios presented do not emphasize the critical need for increased visibility. For instance, using retroreflective materials only during daylight hours would not take advantage of their benefits when conditions are poor. Similarly, limiting use to periods of high traffic volume or only at the start of the workday does not adequately address safety needs across all times when visibility may be challenged. Therefore, the application of retroreflective materials must focus on those conditions where visibility is compromised to ensure the safety of all road users.