Motor vehicle crashes are the leading cause of death among U.S. teenagers, accounting for 36 percent of all deaths of 15-to-19 year olds. About half of those who die are drivers, half passengers. But two-thirds of the deaths of passengers in this age group occur in cars driven by other teenagers.

In a new study using federal data from 1992 to 1997, researchers at the Johns Hopkins School of Public Health found that:

• A 16-year-old carrying one passenger is 39 percent more likely to get killed than one driving alone.

• The likelihood increases 86 percent with two passengers and 182 percent with three or more.

• The rate for 17-year-olds is even higher -- 48 percent, 158 percent and 207 percent, respectively.

• The rate is up to 21 times higher during early morning hours when passengers are present.

The data did not allow researchers to determine whether a greater likelihood of alcohol use with peers present was the cause of the higher fatality rates.

As of January 2000, nine states restricted the number or age of passengers who can ride with new teen drivers. Twenty-eight states have driving curfews -- most of them beginning at midnight.

Source: Li-Hui Chen, et al., "Carrying Passengers as a Risk Factor for Crashes Fatal to 16- and 17-Year-Old Drivers," Journal of the American Medical Association, March 22/29, 2000.

For JAMA text http://jama.ama-assn.org/issues/v283n12
/full/joc90737.html