Red-light cameras began proliferating at suburban intersections in 2009 with the justification that they would prevent crashes.
The same year, the Illinois Department of Transportation raised the dollar threshold necessary to report property damage crashes from $500 to $1,500.
In one fell swoop, reported crashes shrank statewide by 30 percent -- from an average of 413,235 a year to an average of 287,718, IDOT officials said.
How much of the credit for reducing crashes should go to red-light cameras?
To answer that question, the Daily Herald analyzed 55 intersections in 29 suburbs using IDOT reports to determine how valuable red-light cameras are at reducing collisions, the main rationale for issuing $100 tickets to drivers.
At first glance, the data shows crashes decreased at 85.5 percent of suburban intersections after red-light cameras were installed.
But a closer look at cameras installed after 2009 at 14 suburban intersections shows their success rate is much lower. In the majority of cases, crashes dropped before the cameras were put up, coinciding with the 2009 IDOT change, and then rose after the cameras were installed.
The 2009 shift isn't the only problem in trying to objectively analyze red-light camera data. The Daily Herald's analysis also found an inconsistent system of reporting crash data to IDOT and lack of public access to statewide data.
That's why a number of experts and good government groups are calling for greater transparency and reforms in how crash data is reported.
A silver bullet?
IDOT updated the property damage standard in 2009 to reflect higher vehicle repair costs.
"As a result, a lot fewer accidents were reported," surveillance camera expert Rajiv Shah said.
The reduced crash rates partly deflected the public uproar over red-light cameras at that time.
But the decline in crashes did not carry through to 14 suburban intersections where cameras were installed after 2009.
One intersection had incomplete data, but at 10 of the 13 others crashes decreased in 2009 -- before cameras were in place at those locations.
After cameras were installed, crashes increased or stayed the same at eight of the 14 intersections, or 57 percent.
"I think everybody was a bit oversold on the promise of cameras being like that silver bullet and reducing crashes," said Shah, an adjunct associate professor of communications at the University of Illinois at Chicago who has studied and written about red-light cameras.
At Peterson Road and Route 45 in Libertyville, for example, crashes averaged 30.5 a year until 2009, when they dropped to 19. But crashes increased to an average of 33 per year after camera installation.
In Bensenville, crashes averaging 28.5 a year at Thorndale Avenue and Route 83 dropped to 19 in 2009. Crashes rose to 31 a year after the cameras were installed.
Municipal officials, for the most part, didn't see a correlation. IDOT reporting standards for crashes with injuries did not change.
"To draw a conclusion between the increase in standards and the reduction of crashes would be speculation on our part," city of Aurora spokesman Dan Ferrelli said.
Comprehensive data for comparing crash rates at red-light camera locations isn't easy to find.
"It's a hodgepodge, scattershot approach," Illinois Campaign for Political Reform Chairwoman Susan Garrett said, mentioning an ongoing federal corruption trial involving Chicago and former red-light camera vendor Redflex. "For the amount of money invested in this and the corruption associated with it, the results should be disclosed in a way that's understandable."
Consider the following: Some towns post crash results at camera locations on their websites; some don't. Some municipalities list crashes with injuries at camera locations; some don't. Certain towns break down crash types, such as rear-end or angle; others lump crashes together. Some municipalities report crashes only for lanes monitored by cameras; others report all approaches to an intersection.
Obtaining statewide data requires a Freedom of Information Act request and an in-person visit to IDOT offices.
"One of the primary objectives of making the post-installation reports accessible is transparency," IDOT spokesman Guy Tridgell said. "We make them readily available for members of the public interested in learning more about the impact red-light cameras are having on their communities.
"The Illinois Department of Transportation is currently exploring other options that could give us a better picture of how effective the cameras are at improving safety," he said.
The state of Illinois requires municipalities with red-light cameras to provide one- and three-year reports on the cameras. But the data is submitted on paper, not electronically. The law is vague, only requiring a statistical analysis "based upon the best available crash, traffic, and other data."
The law tells local officials to undertake additional studies if crashes have increased in lanes monitored by cameras. However, it leaves it up to their discretion whether to take action to rectify the problem. In a number of cases, the reports are prepared by red-light camera vendors.
Shah supports a comprehensive public database of crashes.
"It should be open to the public to review to be sure these cameras are indeed effective -- and if not -- remove them and put in place a warning program. It would be much more sensitive and transparent."
It's also important data be analyzed by experts who don't have a stake in the game, said P. S. Sriraj, interim executive director at the University of Illinois at Chicago's Urban Transportation Center.
The trouble is "the amount of backlash received (about cameras) makes people go defensive or gun-shy about sharing information," he said.