Development of a CompositePavement Performance Index

Every agency responsible for the maintenance of roadway systems faces the problem of insufficient funding to perform all of the necessary repairs on all pavement sections. Therefore, highway agencies must adopt a pavement management system (PMS) to help set priorities. The PMS includes a method for evaluating pavement performance on a routine basis and identifying sections with a need for rehabilitation or maintenance. A comprehensive evaluation of a pavement section should include surface friction, structural adequacy, pavement distress and roughness. Due to the prohibitive costs, surface friction and structural adequacy are not commonly used in the United States as part of the routine inspection procedure for pavements. Many states in the U.S. use a pavement rating system that is based solely on visible surface distresses, while others use an index based on ride quality alone, to perform the regular evaluation of pavements and to select projects for rehabilitation or maintenance. Some states use a combination of distress and ride quality. The Ohio Department of Transportation (ODOT) utilizes the Pavement Condition Rating (PCR), which is based on surface distress, for project selection. Studies show that pavement roughness is the most important issue for customer satisfaction followed by distress. Roughness may also lead to increased deterioration rates, which in turn increase the severity of the roughness. This report outlines the development of a new performance index for pavements that incorporates aspects of ride quality together with surface distress, for possible adoption by ODOT. The proposed index is called the Pavement Quality Index (PQI). The PQI does not require any new measurements or methods; rather, it simply utilizes procedures that are already in place and well established in Ohio. The PQI is an amalgam of the PCR and the International Roughness Index (IRI). The new composite performance index is expected to result in an increase in user satisfaction with highway systems, together with improved decision-making in the pavement management process.