Not in Iowa, but related to this website because it involves US 63 and the Mississippi River: Last month, the Minnesota Department of Transportation began construction on a replacement for the US 63 bridge at Red Wing. Story: KARE (warning: autoplay).
Construction is expected to take about 2½ years. When completed, 63 will come from Wisconsin and curve the opposite way to meet US 61, slightly decreasing the mileage in the state.
MNDOT has an information page. The rendering video is embedded below.