I just recently returned from a 6,300 mile road trip full of filming and photographing road signs and scenes. The route I took (minus the minor detours to points of interest) is as follows:
I-70 West through PA, WV, OH, IN, IL, into MO
I-55 South to I-44 West through MO and into OK
I-44 West to Kilpatrick Turnpike West (Oklahoma City)
I-40 West through OK, TX, NM, AZ, into CA
I-15 South (from I-40 to I-10)
I-10 East through CA into AZ
I-17 North to Flagstaff, AZ
I-17 South back to Phoenix, AZ
I-10 East to Tucson, AZ
I-19 South to Nogales, AZ
I-19 North back to Tucson, AZ
I-10 East through AZ, NM, TX, into LA
I-12 East in LA (to I-10)
I-12 West in LA
I-55 North through LA, MS, into TN
I-40 West to North Little Rock, AR
I-40 East through AR, into TN (to Nashville)
I-65 North through TN, into KY
I-71 North through KY, into OH
I-70 East through OH, WV, into PA
I took over 5,000 pictures total, and filmed probably 65 hours of road footage. I will be working the next several months to get all this content up onto my site, CrossCountryRoads.com
Hopefully I can get it up quickly for you guys to enjoy!
I was bored, so I made a map to help visualize your routing.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi58.tinypic.com%2Frszzb8.jpg&hash=500e8d69e8993500149b91b9a67cb9072c2cef5f)
Anyway, this route seems to be a combination of two of my own trips (pretty much everything except I-10 and I-71, and I did the part of I-10 east of what you did), and so I'm looking forward to seeing your pics.
What would you say your favorite part was?