Last week's National Transportation Safety Board (NTSB) hearings on the cause of the Interstate 35W bridge collapse were dominated by the technical lingo of the investigators. Finite element analysis. Initiation location. Load redundancies. There was also one oft-repeated phrase combining two words rarely used together: "bridge owners.''
A heads-up to all Minnesotans: The NTSB is talking about you. And while it's hard to think about owning bridges the same way as a home or a car, the reality is that these critical components of daily life belong to the public -- not to politicians, not to transportation officials nor any other bureaucrat. Everyone owns them. Everyone shares the responsibility for ensuring they are maintained and cared for. And when something goes horribly wrong, as it did that hot August rush hour in 2007, everyone has a stake in making sure it never happens again.
Is it possible to rule that out after the detail-filled NTSB hearings? Sadly, no. Are the nation's bridges safer because of the lessons learned from the 35W collapse? Yes, but there's much more work to do. NTSB Chairman Mark Rosenker is right to point out that this investigation has uncovered a frightening gap in the system when it comes to gusset plates -- one thankfully being addressed by new safety policies. But this isn't just about gusset plates and what we know now. The real questions are what other gaps are out there? And what are we as bridge owners doing to make sure they're found and fixed?
The 35W span fell victim to old assumptions about bridge design and safety. According to NTSB experts, our bridge was doomed before the first pier was sunk into the Mississippi more than 40 years ago. A fatal flaw lurked in the blueprints drawn up by designers. Some of the span's main truss gusset plates -- big rectangular metal sheets that hold everything together -- were not nearly as strong as they should have been. It's not clear how or if the design firm did the engineering calculations for these critical components: The work was not in the two sets of design documents uncovered by the NTSB. For 40 years, no one noticed the design flaw or the odd gap in the record as the bridge underwent inspections and tons of concrete were added. It's long been assumed here and elsewhere that gusset plates are overengineered, which is one reason bowing documented in one plate didn't generate concern. Thirteen Minnesotans paid the price for this false wisdom, plunging to their deaths when plates in two locations finally gave way.
The NTSB explicitly did not assign blame to a single event or entity. It cited a number of factors -- the design flaw, the concrete added over the years, the weight of the construction materials on the bridge that fateful day, possibly even the hot weather -- that led to the gusset failure. Officially, the time for looking backward, for assigning blame, is over.
The focus now becomes the thousands of older bridges in Minnesota and across the nation. The good news is that progress is being made. The NTSB on Friday highlighted the need for a better bridge-design review system. Gusset plate regulatory fixes, as well as better calculations of the impact of construction projects, are also important steps. In Minnesota, the appointment earlier this year of new MnDOT Commissioner Tom Sorel, who has deep engineering expertise, inspires confidence.
But this is just the beginning. An alarming number of the nation's bridges are still considered deficient, according to a September report from the General Accounting Office. That the doomed 35W bridge was rated deficient for 17 years -- with its condition never improving during that time -- suggests that systemic reform is needed at MnDOT and other agencies so additional bridges don't slip through the cracks. Information about bridge problems needs to be more easily and rapidly shared among the nation's transportation officials.
We as bridge owners also have an obligation to ensure that adequate resources are set aside for bridge maintenance. As bailouts and other projects compete for the nation's financial resources, infrastructure must not take a backseat. On Capitol Hill, an important piece of legislation would help ensure that the large sums provided to states each year would be used wisely to fix older spans. Too often that money is diverted to other projects. The bill, pushed by Rep. James Oberstar, D-Minn., and Sen. Amy Klobuchar, D-Minn., easily passed the House last summer but is mired in the Senate. Passing the bill would be good policy. It would also send an important signal to state transportation officials: There's no higher priority than the safety of the millions of school buses and commuters who cross the nation's aging bridges each day.