So, you the People's have through the end of April to pick your favorites. You can find the on-line ballot form here.
Illinois is represented by 16 choices. Indiana has none. (Take that!) Kansas has one, in Leavenworth, also known as "the bridge no one really wants to cross unless its outbound". Chicago nominees include the Wabash Avenue bridge, completed in September of 1930 for a mere $1,750,000.
Ramp "Q" Structure, an elevated whipsaw which I believe is on the Bishop Ford Freeway somewhere around Stony Island. (If anyone has tighter info on the exact location, please let me know.)
But don't let that discourage you. This is a contest where ballot stuffing is not only not frowned upon, it's encouraged. You can vote for as many of the nominees as you like, as many times as you want. It's like a classic Chicago election - but legal! Vote early and vote often, here.