What is the minimum diameter for plastic drums?

Answer: B — 18 inches

The minimum diameter for plastic drums used in temporary traffic control is 18 inches. This specification is important because plastic drums serve as critical safety devices to alert and manage traffic in work zones. Their visibility and physical presence help ensure that drivers can clearly see the boundaries of the work area. An 18-inch diameter strikes a balance between being large enough to be visible to motorists and manageable for placement and transportation by workers. Drums of this size are also compatible with many traffic control situations, making them versatile tools in temporary traffic management. Larger or smaller drums may not provide the desired level of visibility or effectiveness, which is why the 18-inch dimension is established as a minimum standard.