What is Runway Surface Roughness?
Smoothness is the absence of undulations in the runway pavement surface that, if severe or extensive enough, could interfere with the safe operation or impair the structural integrity of an aircraft. However, rather than measure and evaluate surface “smoothness”, normally the opposite is done i.e. the degree of “roughness” present in the surface profile is measured and compared against standards that specify when corrective action needs to be taken – for example, to restore surface smoothness with an asphalt overlay. The term surface “roughness” as discussed here should not be confused with the fine-scale surface roughness of a pavement properly known as micro and macrotexture that can be felt by running an open hand over the surface. Although pavements can be rough in a transverse direction (perpendicular to the runway centerline), normally roughness measurement and analysis focuses on the roughness present in the longitudinal surface profile parallel to the direction of aircraft oper
