An estimated 28% of all United States highway bridges are considered deficient or obsolete, according to a study by The Road Information Program (TRIP).
According to the study, about 14% of bridges 20 feet or longer are structurally deficient, and another 14% of bridges 20 feet or longer are functionally obsolete.
TRIP noted that structurally deficient bridges are not necessarily unsafe, but are often posted to carry only lower-weight vehicles. Bridges that are functionally obsolete no longer meet current highway design standards.
However, the number of bridges considered deficient declined 18% from 1992 to 2002—from 199,090 to 163,010—according to an Associated Press computer analysis of Federal Highway Administration data.
The Bush administration has proposed increasing highway and transit financing by 13% to $247 billion over the next six years.