This inventory was the first reevaluation produced by the Historic Bridge Program. This reevaluation was prompted by a review of the bridges evaluated in the inventories from 1987 to 2000 which determined that the demolition of bridges evaluated under these previous inventories had increased substantially. This reevaluation was begun in 2003 and was based on bridge type. The Metal Truss bridges were the first to be reevaluated due to the fact that they were the most impacted by the increased replacement work.