Sustained funding and improved practices over the past 25 years have led to a steady improvement of the condition of U.S. bridges, according to Infrastructure Data Solutions Inc. (IDS). The Federal Highway Administration’s latest National Bridge Inventory data reveals a 12-point decline in the number of bridges deemed structurally deficient over a quarter century. From 1992 to 2016, NBI structures carrying such designation dropped from 118,757 to 55,309, or from 21 percent to 9 percent of the inventory.
|NBI Benchmarking is a new cloud-based data analytics tool available for free to registered users from federal, state and local agencies. It was developed by IDS, whose Bridge Optimizer and Roads Optimizer software helps transportation agencies craft optimal long-range performance-based improvement programs.|
IDS finds the level of structurally deficient bridges trending down in most states over the 25-year period. New York has seen the largest reduction from 9,884 (57 percent of the state inventory) to 1,885 (11 percent). Other significant reductions have been realized in Missouri (27 percent lower), Mississippi (21 percent) and Oklahoma (20 percent). The five states with the highest number of structurally deficient bridges in 2016 are Iowa (4,931), Pennsylvania (4,410), Oklahoma (3,414), Missouri (3,147) and Nebraska (2,326). California continues to have the highest total deck area of deficient bridges, followed by Louisiana, New York, Illinois and Pennsylvania. The number of functionally obsolete bridges nationwide has dropped slightly from 80,461 in 1992 to 75,703 in 2016.
“Despite condition improvements over the past 25 years, big challenges lie ahead,” says IDS President Dr. Mahmoud Halfawy. “Based on our analysis, the average age of bridges nationwide is 36 years, and given that the average design life of most existing bridges is 50 years, a big wave of structurally deficient bridges is expected over the next 20 to 30 years. To sustain past progress, agencies will need to get aggressive in implementing new efficiencies and introduce innovation in bridge preservation, programming and project delivery.” — Infrastructure Data Solutions Inc., Regina, Saskatchewan; 306/790-1415; www.ids.consulting or NBIBenchmarking.com