What height should cones be for nighttime operation according to traffic control standards?

The recommended height for cones used during nighttime operations is at least 28 inches. This standard is set to ensure that traffic control devices are highly visible to drivers in low light conditions. The taller height helps to improve the effectiveness of the cones by providing better visibility, which is crucial for safety on the road, especially at night when visibility is reduced.

Cones that are too short may not be easily seen by drivers, increasing the risk of accidents or collisions with the traffic control devices. Thus, a minimum height of 28 inches enhances the cone's presence in the driver's line of sight, encouraging compliance and facilitating safer navigation through work zones or detours that may compromise the normal flow of traffic.

This requirement aligns with established traffic control standards that prioritize pedestrian and driver safety by ensuring that all traffic control measures are conspicuous enough to convey their intended messages effectively.