A new study suggests it can be dangerous to turn off cameras on traffic lights.

FOX's Lisa Brady reports: 

Researchers comparing annual car crash rates say fatal crashes from running red lights went up by 30 percent after cities turned off the cameras designed to catch red-light runners.

The study by the Insurance Institute for Highway Safety comparing crash rates in 14 cities that ended camera programs with 29 cities in the same regions that continued camera programs, also finding a 16 percent increase in all types of crashes at intersections.

A second part of the study finds lower crash rates in cities that have the cameras, compared to cities that never had them.

The institute funded by Auto Insurers says cameras save lives. Critics argue they're more about ticket revenue than safety.

Lisa Brady, FOX News.