Comparison of Surface Characteristics and Pavement/Tire Noise of Various Thin Asphalt Overlays

ABSTRACT Traffic noise has become a major concern in the last decade and many countries have been looking for solutions to reduce noise levels. The California Department of Transportation (Caltrans) has been using different open graded mixes to reduce highway noise levels and improve wet weather driving conditions. There is a need to identify their noise reduction properties, durability, and safety, and to compare these with other asphaltic mixes. Caltrans initiated a long-term program to investigate and monitor field performance of different open graded mixes and other commonly used asphalt surface mixes. This paper summarizes part of the first-year measurements of relevant parameters from asphalt pavements with different surface mixes. It was confirmed that open graded mixes generally reduce the tire/pavement noise level, and the amount of reduction is correlated with air-void content and surface texture. KEYWORDS: Pavement/Tire NoiseFrictionTexturePermeabilityIRI