If you want to read some very interesting information about traffic cameras, specifically, red light cameras, read the comprehensive study done by the University of South Florida School of Public Health.

Even though I was already of the opinion this is all about revenue, the study is quite an eye-opener. In fact, I would encourage anyone who believes the cameras are a good thing, to read the study. The results line up with every other legitimate study done by several state departments of transportation. The results show that red-light cameras actually increase accidents.
The question arises: Why would a municipality install devices that make the roads less safe? It has to be revenue or ignorance. Do a little research and don't believe what the locals tell you. Also, check into state rules about sending in fine payments and then note the address on the City of Chattanooga website.
Regardless, even if you receive a fine, the city cannot force you to pay it. If enough citizens refuse to pay, the cameras will go away.