Which item is NOT among roadway sampling categories?

• A. Base.
• B. Pavement surface.
• C. Sub grade.
• D. Embankment.

Answer: (B)

Roadway sampling categories refer to the layers that form the road’s earthwork: embankment, subgrade, and base. Each category guides what material is being tested for density, moisture, and compaction as part of shaping the road foundation. Pavement surface, on the other hand, is the wearing layer—the asphalt or concrete that sits on top of the base. It belongs to pavement construction rather than earthwork sampling. So the item that doesn’t fit among roadway sampling categories is the pavement surface. The other three represent the earthwork layers you would sample and test to meet specification, while pavement surface testing focuses on the pavement materials themselves rather than the earthwork layers.