Comparison of New Technology for Measuring Ride Quality

Abstract

Ride quality of a pavement is quantified by a statistical index. The statistical index and the profile device used to assess the index are major variables in pavement smoothness. Due to the wide range of these variables across the United States, a nationwide review of the current ride quality specifications was conducted. A major effort in the industry for acceptance testing is the concept of specifying ride quality based on a percent improvement in ride quality of the layer immediately below the new surface. In order to determine the least variable method of profiling pavement surfaces, three different profile devices were used to collect longitudinal profiles at the National Center for Asphalt Technology Test Track. Profiles were collected on the existing lanes and the reconstructed lanes. The profiles collected made it possible to determine repeatability precision for the profile devices. This information also provided insight in determining if and how ride quality improves with increasing pavement layers. The findings of this research indicate that the type of surface profiled have an affect on the repeatability of the profile device. Also, the length of the test section profiled affect repeatability. Through the placement of each structural layer in the pavement section, the final surface smoothness was improved. However, bumps located in the initial layer profiled were reflected in the final surface. This indicates that every effort should be made to ensure the smoothest possible initial layer.