During the past few years, consumers, politicians, academics and interest groups have expressed growing concern about the safety of using cellular phones in cars and trucks. The increasing use of cellular phones in vehicles is part of a larger trend related to the introduction of technologies that could divert attention from driving.

• A recently published National Highway Traffic Safety Administration (NHTSA) survey reports that 44 percent of drivers have a phone with them when they drive, 7 percent have e-mail access, and 3 percent have facsimile capabilities.

• Estimating that cellular phone use contributes to just under 0.74 percent of total accidents, researchers calculated the costs of drivers' cellular phone use to be $4.6 billion per year (0.0074 times $630 billion).

• About half of this $4.6 billion is attributable to the 300 estimated fatalities associated with driver use of cellular phones, while the other half represents the costs associated with more minor accidents in which cellular phones were a contributing factor.

Net benefits of a ban on cellular phone use for drivers, based on the preceding cost and benefit estimates, would impose annual net costs of about $20 billion ($25 billion in costs minus $4.6 billion in benefits). Costs of a ban are more than five times greater than the benefits.

Alternative solutions to a total ban might be the use of "hands-free devices," voice activated dialing, or policies restricting who may use a phone and under what conditions. Imposing a hands-free mandate would cost users $23 per year, which implies a total cost of $1.4 billion annually.

Source: Robert W. Hahn, Paul C. Tetlock and Jason K. Burnett, "Should You Be Allowed to Use Your Cellular Phone While Driving?" Regulation, Volume 23, Number 3, 2000.