What type of surface should the nose of an attenuator have if it is not striped?

The nose of an attenuator should have a solid fluorescent yellow surface when it is not striped. This choice is correct because fluorescent yellow is highly visible and helps to alert motorists to the presence of the attenuator, which is a critical safety feature designed to absorb the impact of vehicles and reduce the risk of injury. The use of fluorescent colors enhances visibility, especially in low-light conditions, making it easier for drivers to notice the device in advance.

In comparison to the other colors, such as solid red, solid white, and solid orange, fluorescent yellow is specifically chosen for traffic control devices because it provides the highest level of visibility against various backgrounds and lighting situations. Thus, while other colors might serve specific functions in road signage and traffic management, fluorescent yellow is the industry standard for safety and visibility in this context.