This table has been been superseded by the Dec 31, 2007 summary table of noise barrier construction by state or jurisdiction. This new data table can be accessed at: Total Noise Barrier Area by Material Type Through 2007.

Table 2 lists the distribution of barriers by type of material. Earth (berm), masonry block (block), brick, concrete, metal, wood, other materials (e.g., polyurethane) and combinations of materials have all been used to construct barriers.

Table 2 Total Noise Barrier Area by Material Type Through 2004