A pass of a roller is defined as:

A pass of a roller refers to the action of the roller moving over any area one time. This definition is fundamental in understanding the compaction process in asphalt construction. When a roller makes a pass, it compacts the asphalt layer, helping to achieve the necessary density and stability required for the performance of the pavement.

In asphalt applications, the number of passes by the roller is critical as it impacts the final quality of the surface. Typically, a single pass may not provide sufficient compaction, which is why multiple passes are often needed; however, the definition remains centered on the action of the roller covering an area once.

The other definitions provided imply multiple passes over the same area, which extends beyond the standard definition of a single pass. Therefore, the correct understanding of a pass is essential in achieving optimal compaction and overall pavement quality.