September 12, 2007
There are certain things that everyone takes for granted. Street lights, sewage systems, and roads in drivable condition. But driving in Minnesota is a different matter. During the winter the roads are slow and dodgy. In the summer, routes are fraught with detours, highways are down to one lane, and the smell of newly laid asphalt overpowers that of freshly cut grass. The Interstate 35W bridge, one of Minnesota’s major throughways, collapsed on Aug. 1 due to what both Minnesota Rep. Betty McCollum (D) and Eugene Robinson of The Washington Post called a blatant failure in our infrastructure management.
Now, the city has become fragmented. There are ways to physically navigate around where the bridge used to connect the north and south parts of the city of Minneapolis as well as two portions of the University of Minnesota’s Minneapolis campus. But it’s difficult to compensate for the loss of faith in the things we used to take for granted.
The bridge collapse has prompted the creation of a new course at the University of Minnesota taught by Pat Nunnally, a research associate in the Landscape Architecture Department, called “The River, the Bridge, the Community: Beyond the Headlines of the I-35W Bridge Collapse.” The course is intended to get students to rethink defining elements of the university campus. “I’m part of a much broader effort to make the campus as a whole aware of the fact that the Mississippi river goes right through the middle of it,” Nunnally said. “The shock of the tragedy will fade and people will replace that with a growing sense of the significance of the river.” Interstate 35W becomes a dead end before a gaping hole. Its presence has a haunting effect on the campus. Driving down University Avenue, it’s difficult not to see the cliff edge of concrete and metal hanging ominously over the wreckage. And with the neighboring 10th Avenue bridge now re-opened, students cross alongside the vacuum of space above the debris will be reminded of this failure routinely.
So what do we do not only with this bridge collapse but with the rest of the nation’s eroding highway system? The collapse of this bridge is a starting point for questioning the rest of our infrastructure that so vitally connects the country.
“Public policy decisions are made based on competing goods,” Nunally says. “You can never have enough or all of the information, so the decision-making is contingent on what you can find out and act on.” Policy-making became muddied, lost in a volley of different versions of similar facts, colored by varying interests and opinions on the matter.
At the House Transportation Committee hearing on Sept. 5, representatives including James Oberstar (D-MN), Nick Rahall (D-WV), and Michael Capuano (D-MA) among others, argued through their competing senses of what is best for the nation’s infrastructure with Mary Peters, secretary of the U.S. Department of Transportation.
Rebuilding the I-35W bridge is certainly an issue, but lawmakers are also focused on repairing the 740 other bridges built in the same manner and at the same time as the Minneapolis bridge. The National Bridge Inventory has data (PDF) on just fewer than 600,000 bridges. Of these, 80,000 are considered functionally obsolete and 72,500 are structurally deficient. About 1,097 are in Minnesota alone. The National Highway System includes 116,086 of total bridges from the NBI of which 5.3 percent are structurally deficient. The NHS/NBI defines bridges as “structurally deficient”
[I]f they have a general condition rating for the deck, superstructure, substructure or culvert as four or less or if the road approaches regularly overtop due to flooding. A general condition rating of four means that the component rating is described as poor.
The Minnesota Department of Transportation says (PDF) that, according to the National Bridge Inspection Standards, not all structurally deficient bridges are unsafe. This is where the confusion starts. States also set up their own standards for roads that are not necessarily consistent with the national standards. For example, bridges that span 20 feet or less are not considered a part of the National Bridge Inventory and are therefore not inspected by the DoT. In Minnesota, the line is drawn at 10 feet. Similarly, on a national level there is no protocol for inspecting tunnels, so the tasks of creating criteria and carrying out inspections are left to the states.
The I-35W bridge was a deck steel truss bridge that opened for traffic in 1967. Its replacement was scheduled for 2020. This type of bridge has a particularly short life span of about 50 years in comparison with a typical bridge that may last up to 100 years. There are five similarly built bridges in the state of Minnesota. In this particular case:
The poor rating can be attributed to corrosion at some areas where the paint system has deteriorated, poor weld details in the steel truss members and floor beams, bearings that are not moving as they were designed to move, and existing fatigue crack repairs to the truss cross beam and approach spans.
A number of representatives on the House Transportation Committee complained of the number of such bridges in their districts, saying that they are eager to make repairs but are at a loss as to where the money will come from. Nationwide, about 60 percent of gas taxes go directly toward road maintenance, Peters said during the hearing, but that it isn’t nearly enough to meet the costs. The Federal Highway Administration has estimated that it will cost $40 billion a year to maintain the physical condition of our highways and about $60 billion a year to “substantially improve” conditions. In 2005, $21.6 billion was authorized for bridge reparations through 2009. Oberstar says that he does not want long, drawn-out commissions, hearings, and plans, but rather is pushing for an action program that sets in motion the reparation of our nation’s infrastructure.
The debate during the House Transportation hearing showed that the competing facts and opinions make it difficult to come to good policy decisions. Peters continually insisted that there is already a substantial amount of money available for road maintenance. Last month on “The News Hour with Jim Lehrer,” Peters blamed earmarks in the last highway bill. “There are museums that are being built with that money, bike paths, trails, repairing lighthouses. Those are some of the kind of things that that money is being spent on, as opposed to our infrastructure,” she said. Peters argued against Oberstar’s proposed five cents per gallon gas tax to go directly to highway repair and maintenance. Yet, if alleviating congestion and using less fuel are her goals, well-maintained bike trails that can be useful for commuters are an excellent means to that end.
When money gets spent on roads and bridges, the money has to come from somewhere. Minnesota Senator Amy Klobuchar (DFL) has said, in her now-famous audio clip, “bridges in America just shouldn’t fall down.”
The I-35W bridge collapse was the beginning of how we think about and understand our infrastructure. For Minneapolis, trying to move forward means more than just designing an attractive structure of steel and concrete, and it’s more than engineering something that works. It will be a challenge to figure out how to completely redesign urban highways in a way that applies new engineering methods to existing structures while keeping in mind that the other infrastructure in the city will change in the next 15 years. And that will shape not only the area of the river it crosses but the future of the urban landscape as well. For the rest of the country, this tragic awakening will force policymakers to find a way to agree on some sort of priority-based cost estimate and to figure out what exactly needs to be fixed first.