In response to the National Transportation Safety Board-proposed ban on cellphones while driving, the Alliance of Automobile Manufacturers tried to defend hands-free devices. They're "designed to be used in a way that helps drivers keep their eyes on the road," they said, but now it looks like this defense doesn't hold water.

Jim Hedlund, a former National Highway Traffic Safety Administration official, says he conducted research on 300 studies for the Governors Highway Safety Association regarding cellphone use while driving. He said that not a single study showed that drivers who use hands-free devices posed any less of a risk on the road than those without them.

Sweden conducted a similar research study and concluded, "There is no evidence suggesting that hands-free mobile phone use is less risky than handheld use."

NTSB carries no authority to pass a federal law prohibiting dialing while driving, but the recommendations have sparked a public debate about the benefits and legality of such a ban on the state level.

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