Effect of Poor Workmanship and Lack of Smoothness Testing on Pavement Life-Cycle Costs

Pavement performance is commonly evaluated using the concept of pavement serviceability, in which pavement failure is defined by terminal serviceability instead of strict structural failure. The present serviceability index (PSI), the measure of pavement serviceability, is a function of pavement roughness, cracking, patching, and rutting. Pavement roughness is the major component of PSI and represents more than 95 percent of its value. Because roughness is such an important consideration, changes in roughness control pavement life cycles, and, therefore, construction quality, which influences roughness, influences performance and life cycle as well. A case study of a $120,000,000 project is presented. In this project, poor workmanship and lack of smoothness testing led to a considerably high initial roughness. A study was conducted to quantify the long-term effects of the high initial roughness. Results of this study indicate that the pavement service life of the project will be reduced significantly. In addition, a huge increase in the project life-cycle costs is expected. In another study, consideration was given to some of the available smoothness evaluation criteria in which roughness indices, such as the international roughness index and PSI, are used. Results of the study showed that most of these criteria are not capable of adequately addressing the high roughness associated with repeated transverse pumps. Recommendations for overcoming this inadequacy are presented.