Despite improvements made to more than 2,500 bridges in the U.S. last year, there are still more than 58,500 bridges on the structurally deficient list, according to analysis by the American Road & Transportation Builders Association.
Each year, ARTBA conducts a review of state bridge data collected in the U.S. Department of Transportation’s National Bridge Inventory database. ARTBA found that approximately 9.5 percent of America’s 610,000 bridges are classified as structurally deficient, yet these bridges are crossed nearly 204 million times each day, the group says.
The organization said at the rate of last year’s bridge repair, in which 2,574 bridges came off the structurally deficient list, it would take 21 years before all the bridges on the list could be fixed or replaced.
ARTBA states that, while these bridges may not be immediately unsafe, the report is meant to help reveal to the public and policymakers that the bridges have structural deficiencies in need of repair.
“Every year we have new bridges move on the list as structures deteriorate, or move off the list as improvements are made,” said Dr. Alison Premo Black, ARTBA’s chief economist, who conducted the analysis.
In the 2015 report, there were 4,625 structurally deficient bridges that were not classified as so in 2014, she says. On the flip side, about 7,200 bridges classified as structurally deficient in 2014 were repaired, replaced, rebuilt or removed from the 2015 inventory. The net effect, Black said, is a slow national reduction in the overall number of structurally deficient structures.
Iowa leads the way with the most bridges on the list with 5,025, followed by Pennsylvania (4,783), Oklahoma (3,776), Missouri (3,222), Nebraska (2,474), Kansas (2,303), Illinois (2,244), Mississippi (2,184), North Carolina (2,085) and California (2,009).
At least 15 percent of bridges in Rhode Island, Pennsylvania, Iowa, South Dakota, Oklahoma, Nebraska, North Dakota and West Virginia appear on the list. Almost all of the 250 most heavily crossed structurally deficient bridges are on urban highways, particularly in California. Nearly 85 percent were built before 1970.
State-specific bridge information from the analysis and more can be found here.