|Structurally deficient||Functionally obsolete|
|Other freeways or expressways||6.0||20.3|
|Other principal arterials||9.3||22.5|
NOTES: Structurally deficient refers to bridges needing significant maintenance attention, rehabilitation, or replacement. Functionally obsolete refers to bridges that do not have the lane widths, shoulder widths, or vertical clearances adequate to serve traffic demand or bridges that may not be able to handle occasional roadway flooding.
SOURCE: U.S. Department of Transportation, Federal Highway Administration, Office of Engineering, Bridge Division, National Bridge Inventory Database, CD-ROM, January 2005.