UC Davis Institute of Transportation Studies

The work presented in this report is part of an on-going research project, whose central purpose is to support the Caltrans Quieter Pavement Research Program, that has as its goals and objectives the identification of quieter, smoother, safer and more durable pavement surfaces. The research has been carried out as part of Partnered Pavement Research Center Strategic Plan Element 4.19 (PPRC SPE 4.19). In the study documented in this report, field data regarding tire/pavement noise, surface condition, ride quality, and macrotexture were collected over three consecutive years from pavements in California placed with open-graded and other asphaltic mixes. The three-year data were analyzed to evaluate the durability 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 a previous study on the first two years of data collected, which is detailed in a separate report prepared as part of PPRC SPE 4.16, the previous phase of the Quieter Pavement Research Program. 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. The report presents interim results that will be finalized after supplementation with data collected in 2009 as part of the fourth-year (PPRC SPE 4.27) of the study.