These studies came from North Carolina Agricultural and Technical State University and the Virginia Research Council. The results were contradictory.
In certain locations, these cameras were proven successful in preventing accidents.
But, in others, the studies found that the cameras are actually associated with increases in certain types of crashes.
Authorities in Sioux City said these studies over-simplify things and their numbers speak for themselves.
"Traffic accidents on the interstate are down a third since we've put in the speed cameras. Traffic accidents on the intersections with red light cameras are down 49-percent. Traffic accidents across the city are down 15-percent," Capt. Mel Williams, of the Sioux City Police Department, said.
And, Captain Williams said the city was deliberate about where they installed the cameras.
They looked at where the accidents were happening, they asked officers where they had problems with drivers running red lights, and intersections where it may be more difficult to enforce the law.
But, the Iowa Department of Transportation said before a city installs traffic cameras, there are many other counter-measures to try first, like adjusting the speed limit and taking a second look at turn lanes.
And, even though the DOT said the cameras are not always the best option, sometimes they can work.
"If it is put at a location that doesn't have crash, higher than average crash rate, then they're very likely not going to help. On the other hand, if it is a location that definitely is speed or red-light running and higher than normal crash rate there, then yea, definitely they can help," Iowa DOT Director of Traffic and Safety Steve Gent said.
The Iowa DOT is asking cities to turn in as much data as they have about red light and speed camera history by May 1, so they can determine whether or not they're still needed or are effective.
Captain Mel Williams said as far as he knows the city will comply unless the pending lawsuit, where the city is suing the Iowa DOT over their new regulations on traffic cameras, somehow gets in the way.
Williams also provided KTIV with data about the difference in the number of traffic accidents at intersections with red light cameras and those without. In fiscal year 2012, the city reported more than 1,100 accidents at intersections without photo enforcement compared to 117 accidents at intersections with photo enforcement.
Winds ripped dozens of trees from the ground, snapped limbs, and scattered debris. Rain flooded fairways and greens. Monday morning, golf course officials checked out the damage from the storm. More >>
Winds ripped dozens of trees from the ground, snapped limbs, and scattered debris. Rain flooded fairways and greens. Monday morning, golf course officials checked out the damage from the storm.
Persons with disabilities who need assistance with issues relating to the content of this station's public inspection file should contact Administrative Assistant Kathy Clayton at (712) 239-4100 x209. Questions or concerns relating to the accessibility of the FCC's online public file system should be directed to the FCC at 888-225-5322, at 888-835-5322 (TTY) or at email@example.com.