The quick answer is: Who knows?

The city did a study several years ago that analyzed a number of camera locations for the three years before and three years after cameras were installed.

The study, although it wasn’t entirely scientific, showed a 30 percent reduction in angle, or T-bone, accidents at those intersections. Those are the most dangerous crashes.

Surprisingly, it also showed a reduction in rear-end crashes by about 20 percent.

“That was contrary to the trend we’d seen nationally,” said Don Bennett, the city’s traffic engineering manager who oversees the red-light camera program. Some studies in other locations have shown an increase in rear-end crashes, mainly because drivers slam on their brakes to avoid tickets.

The city hasn’t done any studies in the past few years.

Studies across the country have produced mixed results. While some have shown cameras decrease red-light running (and therefore the likelihood of bad crashes), others have indicated that the cameras increase crashes and injuries, particularly rear-enders.

Over the years, city officials have continued the program, citing safety improvements at some of the city’s worst intersections. Some studies have suggested that engineering improvements, such as increasing yellow-light durations, might be more effective in reducing red-light running than the cameras.

Bennett said safety isn’t the only reason to keep the cameras up.

“One of the purposes is to prevent crashes,” he said. “The other is to change driver behavior.”

As part of a new contract with the camera vendor, the city might move cameras to a few new intersections, Bennett said. That would give the city another opportunity to do a “before and after” study of camera effectiveness.

Date posted: August 26, 2009

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