<p><p><strong>Reference(s):</strong></p><p><em>Christopher et al. (2010)</em></p><p><strong>Method Summary</strong></p><p>The objective of proof rolling is to locate areas with soft or yielding material. The technique can be implemented at any point during earthwork construction. Proof rolling observations can be made simultaneously as material is being excavated, hauled, placed, and compacted by observing the equipment used to perform each of these tasks. Although this approach is observer‑dependent, many agencies use the technique to evaluate gross deficiencies including soft, yielding, or pumping subgrade. The objective of this type of process is to correct problem areas prior to the placement and compaction of subsequent fill materials, structures, or pavements.</p><p>Many agencies have developed vehicle configuration specifications, including weight and tire pressures, for performing proof rolling operations and have established a policy on methodology and threshold criteria for acceptable deflections, as well as those requiring remediation.</p><p><strong>Accuracy and Precision</strong></p><p>Proof rolling is utilized because a large area can be observed. However, the method is observer‑dependent and is not a precise test.</p><p><strong>Adequacy of Coverage</strong></p><p>State transportation departments utilize proof rolling during construction to evaluate large areas on project sites to identify gross deficiencies.</p><p><strong>Implementation Requirements </strong></p><p>Proof rolling is commonly used by all transportation departments.</p><p><strong>General Comments</strong></p><p>Proof rolling is an essential part of monitoring construction of embankments, structures, and pavements to both identify the presence of unstable soils which require excavation and to verify that the replacement materials are stable.</p></p>