Drop down to US-90 in Uvalde and take it west to Van Horne. there are several things to see in Brackettville, the Alamo movie set and the old fort, then on to Del Rio, which is a typical border town, but is safe to visit, if you're interested. When you head out of Del Rio, you come to Langtry and the home of Judge Roy Bean, which has several restored buildings. then you cross the Pecos river and there is a very nice pull off on the west side of the road. Most of the small towns you go through have a history and they are worth exploring. The Big Bend area is desolate, but at the same time very interesting. It is high desert(2.5k) and mountains(8k+), so be careful and watch the weather. the town of Alpine has Sol Ross University and many nice old features. The McDonald observatory, east of there is worth the side trip. On down 90 is the town of Marfa and the famed Marfa lights. You can spend a week exploring the length of US-90, from San Antonio to Van Horne and still not see it all.
Roads are excellent 2 lane TX roads. As far as I am concerned, there is nothing to warn you about, as it is beautiful country. We usually stay in Del Rio and then in BB NP or the town of La Jitas. Go and enjoy a true off the beaten path adventure....