TRS: Far-Field Testing of Noise Wall Effectiveness: Survey of State Practice and Literature ScanStatus: CompleteReport Date: 06/15/2012 Summary: Before performing a formal investigation involving such "far-field" testing to confirm MnDOT's view that far-field noise levels do not increase with the installation of noise walls, CTC & Associates was asked to review noise wall testing research and guidance, and contact national experts to determine whether such testing has been performed elsewhere. The scope of this investigation also includes determining how other state departments of transportation have responded to similar complaints. This review doesn't include noise generated by reflection between parallel barriers; Minnesota is investigating this issue by other means. Final Deliverables: Synthesis #TRS1202 Related Materials: Related Research: