A new study made waves in the transportation community last week with data showing red-light cameras reduced fatal red-light crashes by 24 percent in 14 of the biggest cities with cameras.

The study gave camera proponents an opportunity for an "I told you so," and sent foes scrambling to dispute the data. We know plenty of drivers on both sides of the issue here.

This is one of the times the data support the bureaucratic claim that "the cameras aren't there for money," but for safety. Many people don't believe it at first, and even fewer buy the notion after they get the ticket, with a hefty fine, in the mail.

Local data have shown the income from the cameras drops the longer the devices are in place, and other data, including this latest report from the Insurance Institute for Highway Safety, show the cameras prevent serious-injury accidents and fatalities. To make up for the revenue drop, cities can find themselves adding more and more cameras.

So they reduce fatal red-light crashes, but firsthand experience in traffic shows they increase nervousness and confusion behind the wheel. The cameras force some drivers to slow down or change their driving routes altogether.

That's when you find yourself thinking: Why is that person ahead braking for a green light? Oh, that's right. It's a camera intersection, and they're worried they'll have to stop soon.

It seems that avoiding the red-light intersection does not make one a better driver, but the report claims, "Institute studies of camera programs have found that red-light violations fell at intersections where cameras were installed and that this effect also spilled over to intersections without cameras."

Score one for the camera supporters.

Road Runner addresses road-related issues in this column on Mondays. Send your Road Q questions via e-mail to roadrunner@azstarnet.com or to 4850 S. Park Ave., Tucson, AZ 85714. Please include your first and last names.