About the research
Highway noise is one of the most pressing of the surface characteristics issues facing the concrete paving industry. This is particularly true in urban areas, where not only is there a higher population density near major thoroughfares, but also a greater volume of commuter traffic. In 2004 and 2005, the Federal Highway Administration, Iowa State University, and the American Concrete Pavement Association initiated a five-year, multi-million dollar Portland Cement Concrete Surface Characteristics Program. This program is administered through the National Concrete Pavement Technology Center located at Iowa State University. The purpose of the program is to determine the interrelationship among noise, friction, smoothness, and texture properties of concrete pavements. This report addresses work conducted under Part 2 of the program. In Part 2, data were collected on 1,012 test sections totaling 240,000 ft., representing 395 unique pavement textures. This is the most comprehensive inventory of concrete pavement surface textures ever compiled. The inventory includes transverse and longitudinal tining, diamond grinding, various drag textures, grooving, exposed aggregate, shot peening, cold milling, and some asphalt pavements and surface treatments. A preliminary analysis of the data has revealed a number of important findings. For example, relationships between texture and noise are beginning to emerge. These are not based on nominal texture dimensions, however, since a second finding is that nominal dimensions are rarely observed to be found in place. Friction and noise are also found to have no relationship, demonstrating that quieter concrete pavements can be achieved without compromising this important characteristic.