Ban hand-held cell phone use; decrease distracted driving; lower the crash rate.

Seems straightforward, doesn't it?

Not so, according to a recent study by the Highway Loss Data Institute, an affiliate of the Insurance Institute for Highway Safety, which found that states that banned the practice had no discernible difference in the number of crashes before and after the legislation went into effect.

The study looked at the crash rates in four states: California, Connecticut, New York and Washington. Researchers went to intersections and exit ramps to physically observe the number of people using hand-held devices, and while they estimate the drop in use is somewhere in the range of 41 to 76 percent, the crash numbers (total crashes, not just those involving mobile phones) before the bans and after were virtually identical -- something that was obviously puzzling to researchers.

Adrian Lund, who oversaw the study, said, "We still don't think we understand this fully," but noted that some drivers may have switched to hands-free phones, which perhaps posed an equal distraction risk and therefore the numbers did not move. The other possibility, he conceded, was that cell phone use is not as much of a problem as previously thought, ranking just the same as the myriad distractions -- a crying baby, spending too long changing the radio -- that drivers face everyday.

(Source: The New York Times Wheels blog.)