I thought the twining of 31 was completed several years ago, but that may have just been the northern part, close to South Bend. The connection to Elkhart has been done for years. (My inlaws had a house that was demolished to make way for that expansion)
Looking more closely on Google Maps, I see that the new, full freeway quality part is north of Kokomo (or US24).
Further search with Indiana DOT, shows that there is a construction project for several miles on 31 near Indianapolis. And some preliminary work on an intersection on 15 near Goshen.
An interesting novelty on the I DOT travel map - their snow plows have webcams.