Comparison between old and new noise standards in Nagoya City

The Japanese Environmental Agency (now the Ministry of the Environment) updated the environmental quality standards for noise in April 1999. The new standards replaced the median value of percentile level L 50 for noise evaluation with the equivalent sound pressure level L Aeq. The standards renewed the classification of areas and time sections. The most significant change was the introduction of category of artery-road-adjacent area. This report sets the range of the artery-road-adjacent area to 20 m or less from the applicable road to compare the new standards with the old, based on data collected in Nagoya City. The achieved rates for the new standards seem to be on the whole the same as those for the old standards. However, a detailed analysis reveals some differences, such as higher achieved rates in the artery-road-adjacent areas and lower achieved rates in the general areas for the new standards than for the old.