Critics have long contended that traffic light cameras don't increase motorist safety so much as generate revenue for local and state governments. In 2008, for example, the Florida Public Health Review published a research paper that concluded the cameras "actually increase crashes and injuries, providing a safety argument not to install them." In particular, there has been a dramatic increase in rear-end collisions, suggesting that people are slamming on their brakes to avoid a ticket.
Similarly, a 2005 Washington Post report found that after the city installed its traffic light cameras, collisions at the camera-equipped intersections went up rather than down. But the cameras brought the city $32 million in revenue. So rather than halting the program, the city chose to expand it.
A number of researchers have shown that lengthening yellow lights at crash-prone intersections is much more effective at preventing collisions than issuing automated citations. (The North Carolina Urban Transit Institute, for example, came to that conclusion after an extensive study funded by the U.S. Department of Transportation. Other studies along those lines have been conducted by the Virginia Department of Transportation, the Texas Department of Transportation, and North Carolina A&T.) But lengthening yellow lights doesn't add cash to city coffers, so few jurisdictions have considered it. In fact, according to The Newspaper, a website that covers motoring issues, at least six cities have been caught shortening yellow lights after installing cameras at intersections, putting motorists in more peril while simultaneously picking their pockets when they unexpectedly run through red lights.
In many cities, the companies that manufacture the cameras get a cut of each fine, creating some perverse incentives when it comes to weighing safety and revenue. Alternet reported in February that some jurisdictions even let the companies choose where the cameras are located. Until media reports and citizen complaints prompted a change in the law, motorists in Washington, D.C., who wanted to challenge an automated ticket had their claims heard not by a government court but by the same company that received a percentage of every fine collected.
Such policies have sparked a backlash: As of December, 15 states and nine cities had banned automated citation cameras. Whether those bans hold up under tightening budgets remains to be seen.