Here's info on each of the bid cities

Here are some key facts concerning each of the bids:

VENUES:

Chicago: 31 venues in total. 15 existing with no permanent work required; one to be built irrespective of the Olympic Games; six new additional permanent venues, to be built only if Chicago is elected and scaled down after the Games; and nine temporary venues.

20 venues within 10 km of the Olympic Village. 19 venues within 10 minutes and four venues within 10-20 minutes of the Olympic Village. Most of the 31 venues would be located along the lakefront, close to the city center.

A new 80,000-seater Olympic stadium. Post-Games capacity to be reduced to around 10,000.
Reuters report