Many states around the country have put bans on using handheld cell phones while driving on the books. The goal of these laws is to reduce the number of distractions while driving in the hopes of reducing the number of traffic accidents. 

Many states have also enacted bans on texting while driving in addition to talking on a handheld phone while driving. The states with the bans in place do still allow the driver to use hands free devices to talk while driving. A recent study conducted by the Highway Loss Data Institute found that bans on driving while talking on a handheld phone didn't reduce the accident rates in areas where the bans were enacted.

Adrian Lund, president of both the Insurance Institute for Highway Safety and HLDI, said about the study, "The laws aren't reducing crashes, even though we know that such laws have reduced hand-held phone use, and several studies have established that phoning while driving increases crash risk."

The study didn’t pinpoint a reason for why a reduction in accident's hadn't been seen in most areas, but speculation was that perhaps using a hands free device was just as distracting as talking on a handheld phone while driving. The study did point out that a reduction in accidents was noted after the ban on handheld phones in New York, but the reduction had begun before the ban was enacted.

A new study has been conducted by Sheldon H. Jacobson, a professor of computer science and director of the simulation and optimization laboratory at the University of Illinois. The study looked at the relationship between pre and post ban auto accidents using data from 62 counties. Jacobson and his co-researchers published their study in a coming issue of a journal called Transportation Research Part A: Policy and Practice.

Looking at the data the researchers found that after the bans were enacted 46 of the 62 counties in the study saw a reduction in the number of fatal accidents and ten of the counties showed a statistically significant level of accident reduction. The study also showed that the number of accidents after bans dropped was larger in counties like New York, Bronx, and Queens where the population was higher than it was in rural areas of New York.

Jacobson said, "What that suggests is, if you have a congestion of cars and you’re distracted, you’re more likely to hit someone. If you have a lower congestion of cars, you’re still distracted, but you’re less likely to hit anyone because there are less people to hit. It’s simple probability." 

The study performed by Jacobson and his team is different from other studies on the topic in that  it analyzed publicly available data on accident rates published by the New York State Department of Motor Vehicles. The study uses pre ban period of 1997 to 2001 and post ban period of 2002 to 2007 for its comparisons. New York has had a hand held phone ban in place since 2001. The researchers do acknowledge that their data could be skewed by driver education programs and things like major storms and road construction that could increase accident rates.