If your coming from Chicago you'll probably head South on the 55 then pick up 44 south or west down around St Louis to OK City where youll get the 40 west which will take you into Flagstaff and winter in AZ, from Flag pick up the 17 south and that will toward Phoenix. 89a runs off the 17 goes south thru Sedona and a lot of pretty country, but you wanna listened to weather as they close it in bad weather 89a will connect to 89 down to Prescott if you stay on 89 its really scenic and will take you to 93 take that into Wickenburg then pickup the 60 S. to Phoenix. The drive from Flagstaff to Phoenix can be done in a day with short stops to fly eat what ever. I've made that run many times both ways. its awesome.