route to hill country and marfa, tx from memphis,tn area

If you want to avoid Dallas traffic, take I-40 to Oklahoma City, I-44 from there to Wichita Falls, Texas (I-44 ends there), then 281 south all the way to Johnson City. Some of this road is 4-lane, some is not, but it is a good road. We take this route often from our home in SW Oklahoma all the way to San Antonio. There is a Walmart Super Center in Marble Falls, TX with easy access from 281 for last minute shopping. Johnson City is another 22 miles south of Marble Falls.

GM

thanks bb,this is type info I needed. sincerely,richard

Unless just have some reason to go as you say, the following is the easier and quicker route.
Coming into east side of Dallas, take I-635 south to I-20, west to I-35E, then south to Georgetown, TX 29 west to Burnet, US 281 south to Johnson City. Approach Dallas after 10 am and before 4 pm or on a weekend and most likely you will have little traffic problems. You will have some traffic and some construction on parts of I-35 but again probably no problems. The day or two after Christmas will likely be heavy though.
All interstate to Georgetown then all 4 lane the rest of the way.
We make the trip to Fredericksburg, west of Johnson City, several times each year.