What is the requirement for cones on high-speed roads greater than 45 mph during nighttime?

The requirement for cones on high-speed roads greater than 45 mph during nighttime is that they shall be retroreflectorized with at least two white bands and must be at least 28 inches tall. This specification ensures that the cones are highly visible to drivers, especially during low-light conditions.

The retroreflectorization is vital because it enhances the visibility of the cones when illuminated by vehicle headlights, thereby improving safety by clearly delineating work zones or hazards. The requirement of having a minimum height of 28 inches helps to make the cones more visible from a greater distance, allowing drivers ample time to react to changing road conditions.

Ensuring that cones meet these standards is crucial for maintaining traffic flow and minimizing the risk of accidents in environments where vehicles are traveling at higher speeds. Cones that do not meet these visibility and height requirements would likely not serve their intended purpose effectively, potentially leading to unsafe driving conditions.