UC Davis Institute of Transportation Studies

Field data regarding tire/pavement noise, ride quality, and macrotexture were collected over five consecutive years from pavements in California placed with open-graded and other asphaltic mixes. The five-year data were analyzed to evaluate the ride quality and effectiveness of open-graded mixes in reducing noise compared to other asphalt surfaces, including dense- and gap-graded mixes, and to evaluate the pavement characteristics that affect tire/pavement noise. The analysis in this report is a supplement and update to four previous studies on the first four years of data collected, which are detailed in four separate reports. Models have been updated, with some changes in the use of condition survey variables. Conclusions are made regarding the performance of open-graded mixes and rubberized mixes (RAC-G), comparisons are made with dense-graded mixes (DGAC), and the effects of variables affecting tire/pavement noise are examined. Tire/pavement noise is greatly influenced by surface mix type and mix properties, age, traffic volume, and the presence of stresses indicated by pavement surface macrotexture, which served as a substitute for raveling in this study. Noise levels generally increased primarily with traffic volume and pavement age. Overall noise levels decreased with increased surface layer thickness and permeability (or air-void content).