The Effect of Initial Pavement Smoothness on Long- Term Roughness Progression: Some Findings from C-ltpp and Us-ltpp Studies

This brief provides findings on the observed effect of initial pavement smoothness (also known as initial roughness, or as-constructed roughness) on the long-term pavement roughness progression of asphalt overlays. The relationship can be used as a measure for estimating the long-term effect of pavement smoothness and for consideration when developing smoothness specifications and/or payment adjustments within a smoothness specification. This brief summarizes research completed by the University of Waterloo through the C-SHRP Graduate Research Program and is intended to complement C-SHRP Technical Brief #16 entitled Summary of Pavement Smoothness Specifications in Canada and Around the World.