Just how sturdy are the nation’s bridges?
The rush-hour collapse of the Interstate 35W bridge over the Mississippi River in Minneapolis in August has triggered shock waves of concern about the condition of the nation’s bridges. Shortly after the disaster that killed 13 people, state and local governments immediately began inspecting bridges in their jurisdictions, particularly those with the same design as the I-35W span. Local government officials say they need an influx of state and federal money to fix troubled bridges that have already been identified in their areas.
At the time of the collapse, the I-35W bridge was listed as “structurally deficient” on the National Bridge Inventory (NBI). Specifically, the bridge’s superstructure was listed in “poor condition” on the NBI, but it also was listed as meeting “minimum tolerable limits to be left in place as is.” That is not unusual, says Tony Giancola, executive director of the Washington-based National Association of County Engineers (NACE). “Just because [a bridge] is structurally deficient doesn’t mean it has to be closed,” Giancola says. “It just means it has to be more closely monitored.”
State and local transportation agencies generally schedule structurally deficient bridges for repair or rehabilitation, and county engineers may post weight restrictions on small local bridges. According to the U.S. Department of Transportation, there were more than 73,000 structurally deficient bridges nationwide in 2006.
Increased funding will be a major tool to fix the problem, Giancola says. “Infrastructure has traditionally been under-funded, and it’s not just the big projects we’re talking about,” Giancola says. “We’re talking about maintenance, operation and dollars to maintain these bridges.” That includes more frequent inspections to identify scouring around bridge foundations caused by currents and to check the superstructure for weak points.
One week after the Minneapolis bridge collapse, House Committee on Transportation and Infrastructure Chairman Rep. Jim Oberstar, D-Minn., announced a plan to fix the nation’s bridges. It includes improved bridge inspection requirements, dedicated funding that will be distributed based on public safety needs without earmarks, and establishment of a trust fund to provide revenue for the repair or replacement of structurally deficient bridges. In a separate bill signed into law on Aug. 6, Congress also waived a $100 million limitation on emergency relief funds to allocate $250 million for the repair of the I-35W bridge and $5 million to relieve traffic congestion caused by the collapse. “We cannot wait for another tragedy,” Oberstar said in a statement. “We must act, and act quickly.”
States also may provide some increased funding. From 2001 to 2003, the Oregon Legislature passed three Oregon Transportation Investment Acts (OTIA) that included approximately $350 million for city- and county-maintained bridges. The money was distributed according to need, as determined by the sufficiency rating of each bridge, says Jon Oshel, county road program manager for the Salem, Ore.-based Association of Oregon Counties. “[Of] all the deficient bridges at the time that we got all the money, it took care of about a third of them,” Oshel says.
Polk County, Ore., received about $14 million to replace and repair nine bridges, all of which were more than 40 years old, says Polk County Public Works Director Aaron Geisler. “Some of these bridges were in danger of being closed down, and they served vital links to our forest areas where a majority of our economic base is the harvesting of timber,” he says. Those bridges now have been repaired or replaced and are once again able to bear heavy logging trucks.
Polk County would not have been able to afford the work without OTIA funds, Geisler says. “We would be sitting here, arguing over the few bucks that we do receive, and the bridges would be in more intolerable shape than they were,” he says.