Now that it's against the law in California to talk on a handheld cell phone while driving, large numbers of drivers are rushing to get hands-free phone devices for their cars. They plan to keep talking and driving, and they don't want to get a ticket.That's understandable, but they should not assume that hands-free phoning while driving makes them safer.

It doesn't.  Studies have consistently shown that hands-free phones don't do much to reduce the risk of accidents from driving while talking on a phone. The Insurance Institute for Highway Safety sites two studies involving actual crash victims: one in Canada in 1997, the other in Western Australia in 2005. Those studies show that cell phone users are four times as likely to get into crashes serious enough to injure themselves or damage property than are drivers who don't drive and talk on the phone.While the studies were unable to determine the benefits of placing a call with a hands-free device, once the conversation begins, the elevated risk of accidents were the same for both drivers with hands-free cell phones or handheld models.As the studies consistently demonstrate, it's not about the hands.

It's the driver's brain or cognitive abilities that are impaired while talking on a phone and driving. Their perception and judgment, their ability to react or even to be aware of what's going on around them is diminished. Reaction time is slowed. They are more likely to swerve.Drivers are also distracted by conversations with other passengers in a car. But the other passenger is aware when the driver approaches a difficult driving situation – entering a packed freeway, for example, or a dangerous intersection – and is more likely to slow the conversation or stop talking. By contrast, the person on the other end of the telephone is dangerously unaware.A hands-free cell phone will prevent you from getting a ticket. But if your goal is to avoid an accident, the best advice is hang up and drive.