So many questions in this thread. Most traffic ticket attorneys offer free consultations. Just google then and call them. (but get to the point, don't chew their ear off:))
Every area has a different threshold of when the cops start stopping you. The Palisades in NJ is 70 M.P.H. 69 is kosher, 71 and they hit you. I87 depends on the area you are driving through, but for most of the way (without a work zone) 75 is ok, at 80 you are pushing it. I have heard, (and practiced) that up to 80 on the OH turnpike is ok, over 80 and they are all over you. Very well deployed they are in OH!
The moral of the story is? When you come to a Town, don't break all the laws before you know what they expect of you. If the sign says 50, try it out once or twice and save yourself the headache.