Abstract
In recent years, there has been a proliferation of knowledge concerning highway noisegeneration and control. There has also been many kilometers of noise barriers constructed.Two countries that have led in the area of highway noise control are Japanand the United States. Each country has developed an accurate prediction methodology, although there are significant differences between them. One objective of this paperis to discuss these differences, as one way of introducing the United States methodinto the international literature. The other objective of the paper is to present a methoddeveloped by the authors to quantify the insertion loss degradation caused by the presenceof parallel reflective highway noise barriers. This method allows the user to locatespatially all image sources, and to determine their magnitude. Comparisons with results from scale model studies indicate that this method is quite accurate.
