In my state, if you're caught driving faster than 15 mph over the posted speed limit, you can be charged with reckless driving. If you think regular speeding ticket fines are high, just wait until the reckless driving charge is included.
I was driving down a steep mountain one time and a state trooper pulled me over for speeding. He told me the radar gun indicated I was driving 20 mph faster than the posted speed limit of 55 mph. He decided not to charge me with reckless driving because I was going down a hill at the time. I didn't figure I could beat that speeding ticket in court, so I mailed in the ticket with the fine.