razorking and I went to Texas last week. We left Tuesday night (June 6th) and returned Tuesday night (June 13th). Whew, what a trip!
There were a couple things that we thought were interesting related to our trip.
Highways that go west & east are even-numbered and highways that go north & south are odd-numbered. Some highways may not exactly appear to be going directly west, but more west than north/south in a way. If an even-numbered highway connects to another even-numbered highway, it's probably curved a bit north at the last minute before ending and changing to another highway or splits into two highways.
Another thing, when driving on the highway... driving south or west, the highway markers will decrease. When driving north or east, the highway markers will increase. If you're driving south, it would be very helpful for you to determine how far from the border of that state you are in. Even though the highway doesn't end at the border, the number will still go down to 0 at that border. If you're driving south on a highway and you just drove by highway marker 133, you know you're 133 miles away from the border of that state. However, when driving north or east... sorry. You won't know how far you're going unless you know the actual number of the final marker at the next border.
Anyway, it was a great trip. :)