FIELD EVALUATION OF TRAFFIC NOISE REDUCTION MEASURES

AS PART OF A CONTINUING RESEARCH PROGRAM, APPROXIMATELY 400 ACOUSTIC NOISE RECORDS PLUS SUPPORTING TRAFFIC AND ENVIRONMENTAL DATA WERE ACQUIRED IN THE VICINITY OF SIX HIGHWAY SITES REPRESENTING FOUR TYPES OF TRAFFIC NOISE REDUCTION MEASURES: ROADSIDE BARRIERS, ELEVATED HIGHWAYS, DEPRESSED HIGHWAYS, AND ROADSIDE STRUCTURES. THE ULTIMATE GOAL OF THE NOISE SURVEYS WAS TO VALIDATE OR MODIFY AS REQUIRED THE NOISE REDUCTION PREDICTION PROCEDURES OUTLINED IN NCHRP REPORT 117. TO THIS END, THE TRAFFIC NOISE DATA WERE CONVERTED TO NOISE REDUCTIONS AT SPECIFIC LOCATIONS IN TERMS OF A-WEIGHTED L SUB 50 (MEDIAN) SOUND PRESSURE LEVELS AND THEN COMPARED TO THE PREDICTED NOISE REDUCTIONS. AGREEMENT WAS ASSESSED IN TERMS OF THE LEAST SQUARES LINE FOR THE MEASURED VERSUS PREDICTED NOISE REDUCTIONS AND THE AVERAGE DISCREPANCY BETWEEN THE MEASURED AND PREDICTED RESULTS AS A FUNCTION OF THE RECEIVER DISTANCE FROM THE ROADSIDE AND HEIGHT ABOVE THE GROUND. THE RESULTS INDICATE THAT THE BEST AGREEMENT BETWEEN THE PREDICTED AND MEASURED DATA IS PROVIDED BY THE ELEVATED HIGHWAY AND ROADSIDE STRUCTURES CONFIGURATIONS. FOR THE ROADSIDE BARRIER AND DEPRESSED HIGHWAY CONFIGURATIONS, THE PROCEDURES OF NCHRP REPORT 117 APPEAR TO UNDERPREDICT THE NOISE REDUCTIONS AT THOSE LOCATIONS WHERE THERE IS NEARLY A DIRECT LINE OF SIGHT TO THE TRAFFIC FLOW. BASED ON THESE RESULTS, MODIFICATIONS TO THE NOISE REDUCTION CURVES IN NCHRP REPORT 117 ARE DERIVED AND PRESENTED.

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 22-31
  • Monograph Title: Noise abatement and control
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00224470
  • Record Type: Publication
  • ISBN: 0309021790
  • Files: TRIS, TRB
  • Created Date: Jan 11 1974 12:00AM