When New Army Post Road (very temporarily IA 5) was built south and west of the Des Moines airport, it left behind the street running west from 42nd Street (the old intersection of IA 5/28). The road is still paved, but is lightly traveled, and is now subject of a bridge project.
A press release from Polk County Conservation details what’s going to happen to the Great Western Trail that runs under the Old Army Post Road bridge just east of IA 28. The trail uses an old Chicago and Northwestern Railroad alignment. The trail will have slight detours while the bridge is removed.
But is the bridge going to be replaced? The press release says nothing about that, but I believe it is. There’s a City Council document from last year (PDF) where the city mentions getting a Clean Water Act permit to “place fill within Waters of the United States” for a project “also known as the Army Post Road Bridge Replacement Project.” So I think there is going to be a new bridge. Otherwise, that McKinley-42nd-Old Army Post hook would be a long dead end.