Auugh,, I think your the one that told me about that ride a few months ago.. Is it just my beginner bike (or maybe arms) but doesn't part of that ride kill your shoulders, I thought I was riding on cobblestone.
I think your way to fast for me anyway.. I average 14-15 mph
There is a section of chip seal (hey, this IS Texas). But, most of that route is brand new asphault. Make sure you have your elbows flexed if you are riding on the hoods.