Iowa’s second diverging diamond interchange, I-35 at 1st Street in Ankeny, will begin to open this week. It will be a long process, beyond the delay announced earlier this year.
According to the DOT, 1st Street will open Thursday, and one ramp will open each week for the next three weeks. However, there will be a delay until the last ramp (SB exit) opens and ends work on the interstate.
More diverging diamonds are planned for Cedar Rapids.
UPDATE: This Des Moines Register article has an image of the construction plan, where you can make a before/after comparison and see how the mainline is being moved.