I am not a lawyer but everyday hwy driver. Here is advices.
1 In america, if you see hwy police car. you should be behind that car for your sake.
2. even 1 mile over limit speed, hwy police can give you ticket depend on his mood. that is the reason almost everybody staying behind police car.
3 I don't know about Texas,but usually not over 5 miles will be dismissed by judge.
4. when you get a ticket, is it written on that ticket what you should do ? ( plus how much your speed was )