A trip over the I-74 bridge
On a recent trip to take some friends to the QCA airport, we drove over the magnificent I-74 bridge (suspension bridges are my favorite). The bridge spans the entire width of the Mississippi River and is a modern marvel. The only problem is, the bridge isn’t modern (over 70 years old), and isn’t marvelous (in disrepair). According to the TIGER discretionary grant application, the bridge isn’t 100% ‘sufficient’ to stay in service. What does that mean exactly?
Sufficiency rating is a numeric value developed by the FHWA. It ranges from 0 to 100 and is indicative of the bridge sufficiency to remain in service. A bridge with a sufficiency rating of 100 would represent an entirely sufficient bridge. Sufficiency ratings of the bridges along the I-74 corridor range from 42 to 98, with the westbound and eastbound Mississippi River bridges rated at 42 and 61, respectively, by the Iowa DOT.
Is the I-74 bridge safe?
So that begs the question, at what point is a bridge too insufficient to carry traffic? The good part is that there are now funds set aside for creating a new bridge. The bad part? Clearly this bridge should be replaced soon… before the sufficiency is too low to support traffic. Thanks to @ashleybridget for the tip.