When compacting an unconfined edge, the steel roller overhang over that edge should be about:

When compacting an unconfined edge, it is essential to ensure that the steel roller's overhang is adequate to provide proper pressure and compaction to the edge of the asphalt layer. An overhang of about 6 inches ensures that the roller adequately compresses the material close to the edge, reducing the risk of lateral displacement or damage and ensuring uniform density throughout the compacted asphalt.

The choice of 6 inches strikes a balance between effective compaction and the prevention of edge cracking or other issues that might arise from inadequate covering. This measurement allows the roller to exert sufficient pressure on the edge without risking edge failure.

In contrast, smaller overhangs may not apply enough pressure to achieve the desired compaction, while a larger overhang might lead to excess stress on the unconfined edge, potentially causing it to rupture or become misaligned. Thus, the choice of 6 inches is a critical consideration in achieving a strong and durable asphalt pavement edge.