It depends on how much time you have and what you want to see. Going through Springfield and Bloomington will take about 5 hours and is not particularly scenic. Staying on the river road to Davenport turns it into an all-day evolution. Davenport to downtown Chicago is about a 3 hour drive on I-80 or I-88, about 2.5 hours into the western suburbs.From there should i keep heading north to Davenport or back east through Bloomington and Springfied to get to Chicago?