They're doing construction on 635 to widen it so lately its been horrible, but its no where as bad as 35 on a regular basis.
Stay away from Houston because, unless you're driving at 4am, you will be stuck in traffic.
Apart from all the small towns, Texas is amazing... The weather right now is a chilling 60 degrees F.
Well if he's coming West to East from I20 he'll avoid 635 altogether and I35E at its worst, the junction with I30 - providing he doesn't go into Dallas at all.
If you do go anywhere near downtown D town be sane and try and do it in the late morning/afternoon/very late evening. 3PM-7PM you're facing Carmaggedon on an epic bullshit scale. If you're not stopping in Dallas just take I35-W south from I-20. There's a bakery/convenience store I get 'talked' into stopping at in West, Tx just after I35 recombines. Yay pastries.
Edit: I just realized he'll go through downtown Dallas when he come's back up from Austin to go to Nashville. Try to avoid the bullshit times I mentioned, I30 through Downtown Dallas is as driving on a freeway that was built in the 50's and expanded by one lane since. It's beyond a terrible mess and I can only shudder in horror how they'll fix that cluster fuck of a system that they dug there.
Czech stop. A MUST on the way to Austin.
http://www.czechstop.net/home.php
Also, the Cross Roads Diner near Downtown was voted one of the best in the U.S.
http://crossroads-diner.com/#/WELCOME-01-00/
This one hundred thousand times. Ever had a pig in a blanket? Imagine that, with shredded meat in the middle instead, and 100 times better. That is their kolaches. I would say stop around Dublin, TX for a Dublin Dr Pepper but that just got shut down... Damn you Dr Pepper.
Lol @ how this quickly got turned into a Texas driving thread.
And I'm off; I made a twitter account to post updates and photos occasionally. Don't care about follower count, but if you're interested, you can check it out occasionally.
https://twitter.com/#!/PaulHaviland
Here's hoping I never have to use my new AAA membership.