The following bridges carry at least 10,000 vehicles a day and have been rated as either structurally deficient or functionally obsolete by inspectors, according to an msnbc.com analysis of the National Bridge Inventory.
Status of "D" means the bridge has been rated structurally deficient; "O" means it has been rated functionally obsolete.
A structurally deficient bridge is closed or restricted to light vehicles because of its deteriorated structural components. While not necessarily unsafe, these bridges must have limits for speed and weight.
A functionally obsolete bridge has older design features and, while it is not unsafe for all vehicles, it cannot safely accommodate current traffic volumes, and vehicle sizes and weights.
The raw dataset of the National Bridge Inventory, which is compiled by the U.S. Department of Transportation's Federal Highway Administration from state reports, was provided by the National Institute for Computer-Assisted Reporting at the University of Missouri. The analysis was done by msnbc.com. This page reflects inspections through December 2005.
