Here in Texas, there isn't really a set speed limit per se. It's a "recommended" speed limit. So you can usually get off if it's not too much over.
I've had about 4 speeding tickets get dismissed for one reason or another, for a $55 attorney fee
Do they have deferred adjudication where you are? Just pay the court fee, don't get another ticket in 3-6 months and it doesn't go on your record.