EVEN Project: Experiment to Compare and Harmonize Methods for Assessment of Longitudinal and Transverse Evenness of Pavement

Abstract

The analysis performed on longitudinal profiles measured on in-service roads during the Permanent International Association of Road Congresses—World Road Association (PIARC) second international experiment, the EVEN project, which was conducted in the United States, Japan, and Europe in 1998, is described. The European experiment was carried out by the Forum of European Highway Research Laboratories, but the results of the European experiment are not included. In the United States and Japan profile measurements were obtained for a number of in-service roads that have various levels of evenness, ranging from approximately 0.6 to 6 m/km. Tests were performed with all devices at different speeds. An analysis of the correlation between the international roughness index (IRI) for the test sections on the basis of the measurements obtained with high-speed devices and the true profile obtained with a combination of three different hand-operated profiling devices is provided. A detailed analysis of measurements was conducted for the test sites for which the poorest correlation between the IRI obtained with the high-speed devices and the true profile was found. Also, a detailed analysis was carried out for the test sections for which the best correlation between the high-speed devices and the true profile was obtained. Finally, the results of an analysis of the repeatabilities and the reproducibilities of the participating devices in United States and Japan are presented.