Just as West Virginia's Silver Bridge collapse in 1967 marked a new era for bridge inspections and awareness of U.S. infrastructure issues, so will Minnesota's Interstate 35W bridge collapse be another ante-upping chapter. The chapter is still being written. U.S. Dept. of Transportation Secretary Mary Peters has vowed a “top-to-bottom review” of federal bridge inspection guidelines. The specific structural issues that may be reshaped depend largely on what the National Transportation Safety Board will determine from its investigation.
Fatigue cracks, lack of redundancy, bearings corrosion, welding codes—a variety of possible factors have been thrust on the national stage. But engineers caution against premature theories regarding why the 40-year-old steel truss bridge collapsed Aug. 1. What does seem clear is that this will lead to updates in inspection guidelines, increased use of monitoring technologies and renewed attention to the complex issue of funding.