The main concern, however, is to come up with information that the DOT would be able to accept and use economically, according to Dr. Moon.



"When these technologies became available in the late '90s and early 2000s, [their designers] were saying, 'These things are going to fix all your problems,'" Moon said. "There's a great deal of skepticism [from the DOTs]—we're been sold before, and we never saw any value. What I really hope for this project is that we begin to bend that curve back around. Yes, the technology is not the solution to all your problems, but yes, it is tools for the toolbox that makes sound and engineering sense."



According to a preliminary report released in late June by CAIT, the nameless bridge "was deemed safe by all the researchers. Issues noted were fatigue cracking, issues with bearings, water infiltration, and presence of a gas line under the bridge that is “potentially problematic.” However, most of the discussion focused on the excessive vibrations that were measured in ambient and induced load tests. High vibration amplitude and frequency of excitation could lead to accelerated deterioration, especially if trucks are creating or adding to the resonance—a vibrational “snowball effect”—which may worsen existing fatigue cracks and other problems. 



The atypical vibration on the bridge could also account for pockets of delamination found in the deck, which Gucunski says is often seen on these kind of bridges.



The CAIT team will release a final report outlining its findings and comparing all the different approaches to testing in August.