As a Las Vegas traffic ticket lawyer I have dealt with hundreds of traffic tickets. First of all, you should not speed. Nevertheless, in my opinion, the vast majority of speed traps are only designed for raising revenue and not public safety.
The main reasons that I say this are as follows:
Speed Traps Are Unfair - In many rural areas, within a few feet, the posted speed limit changes from 45 to 25 MPH within a few feet. This means that you will be hard-pressed to slow down quick enough to reach the posted speed limit.