Cops have been seen anywhere from exit 112 (rare) to exit 96, mainly grouped around exit 100. Standard procedure is to have two cars, facing opposite directions in the center median. Right before entering the town of liberty, there is a large hill that you will crest, and at the bottom of the hill there will be a police officer with a radar/lidar gun. Don’t bother asking to see the laser readout, it will be "in the other officer’s car." Fortunately, if you can find a local lawyer, you can get the penalty reduced. After all, they just want your money, they aren’t interested in your points or safety.