First, the gist of the laws: you cannot hold a phone and have a conversation when driving, although you can touch the phone to dial. If you are 16 or 17, you can't use a phone period. And, the law fails to address text messaging. Here's a link to a Q&A I wrote recently on the laws.
Second, I wanted to address the most important point of such a law: will it make the roads safer? My former colleague Myron Levin, whose story in March in The Times has this juicy detail:
Indeed, federal highway safety officials drafted a letter from then-Transportation Secretary Norman Y. Mineta to the nation's governors in 2003 to warn against laws like California's that allow hands-free calling. For reasons never fully explained, the letter was neither signed by Mineta nor sent. According to the bluntly worded letter, obtained by The Times, "overwhelmingly, research worldwide indicates that both hand-held and hands-free phones increase the risk of a crash."
There has been a lot of research on the subject, with mixed findings. Here's a summary of some of the best-publicized research. If I'm leaving a study out, please note it on the comment board:
University of Utah:
Studies released in 2006 and 2008, respectively, concluded that drivers on cellphones -- hands-free or not -- drove as badly as those under the influence of alcohol and also were prone to clog traffic because they weren't paying sufficient attention. Here's a link to an earlier post on U of U's research.
Carnegie Mellon University:
In a study released earlier this year, researchers found that people talking on a cellphone while driving -- again, hands-free or not -- were devoting 37% less of their brain to driving.
California Public Policy Institute:
The May report concluded that the hands-free law will result in a drop of about 300 driving fatalities each year -- mostly from crashes in adverse conditions.
New England Journal of Medicine:
The 1997 report, based on studying crash data and cellphone bills, showed that motorists were four times more likely to be involved in an accident when using a cellphone versus when not. However, the report also found "Thirty-nine percent of the drivers called emergency services after the collision, suggesting that having a cellular telephone may have had advantages in the aftermath of an event."
Harvard Center for Risk Analysis:
A 2003 study projected that, across the U.S., 2,600 people die each year and more than 330,000 are injured as a result of cellphone-related crashes -- a number that got a lot of media attention with little mention how it was calculated. Overlooked, perhaps, was that the numbers were not based on figures from each state but on a complex calculation involving several factors -- i.e., how much time people talk on the phone and how much they drive.
Statistics from the states:
New York state was the first to institute its hands-free law in 2001. The state also keeps statistics on contributing factors to accidents. From 2001 through 2006, hand-held phones were a factor in 1,170 crashes versus 214 crashes involving hands-free phones, according to the New York State Department of Motor Vehicles. There are some important caveats here: accident factors were reported in 82% of all crashes, and in many instances the police must count on getting data from those involved in accidents -- who may or may not have seen what happened or may or may not be honest about it.