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Analysis of Strategies To Control Traffic Noise at the Source: Implications for Policy Makers

Traffic noise control strategies that reduce traffic noise at the source were identified. The strategies were grouped according to the vehicle noise sub-sources: engine, intake air, exhaust, cooling fan, transmission/driveline, and tire/pavement. Examples of the strategies and recent advancements in vehicle noise control are given. The analysis yielded a number of implications for policy makers. In the United States, market forces are currently fostering technological advancements to reduce most of the vehicle noise subsources. However, the reduction of tire/pavement noise, the dominant subsource at freeway speeds, is currently benefiting little from market forces and may be hindered in the future by trends in passenger car tires. Policies and regulations, where warranted, should be aimed at reducing tire/pavement noise through a concerted effort on the part of both tire and pavement industries as well as transportation agencies.