While this structure may look like a concrete arch, it is indeed a concrete slab.
This exterior faux arch was built as a decoration.
It was built in 1923 as part of an improvement plan by the Rock Island.
The bridge is an extremely deteriorated condition, with both fake arches in danger of collapsing.
It is a simply built span, consisting of the single concrete slab span resting on concrete abutments.
Overall, the bridge appears to be in poor condition. The author never advocates for replacement, but this bridge has serious structural issues.
Because of this, the author has ranked it as being locally significant. Despite it being a unique underpass, it is still a common design and more modern.
The photo above is an overview.