Context Injuries from motor vehicle crashes are the leading cause of death among
teenagers. Carrying passengers has been identified as a possible risk factor
for these crashes.
Objective To determine whether the presence of passengers is associated with an
increased risk of crashes fatal to 16- and 17-year-old drivers and whether
the risk varies by time of day and age and sex of drivers and passengers.
Design and Setting Incidence study of data from the Fatality Analysis Reporting System
and General Estimates System (1992-1997), as well as the Nationwide Personal
Transportation Survey (1995).
Subjects Drivers aged 16 and 17 years who drove passenger cars, vans, or pickup
trucks.
Main Outcome Measure Driver deaths per 10 million trips by number of passengers, driver age
and sex, and time of day; and driver deaths per 1000 crashes by passenger
age and sex.
Results Compared with drivers of the same age without passengers, the relative
risk of death per 10 million trips was 1.39 (95% confidence interval [CI],
1.24-1.55) for 16-year-old drivers with 1 passenger, 1.86 (95% CI, 1.56-2.20)
for those with 2 passengers, and 2.82 (95% CI, 2.27-3.50) for those with 3
or more passengers. The relative risk of death was 1.48 (95% CI, 1.35-1.62)
for 17-year-old drivers with 1 passenger, 2.58 (95% CI, 2.24-2.95) for those
with 2 passengers, and 3.07 (95% CI, 2.50-3.77) for those with 3 or more passengers.
The risk of death increased significantly for drivers transporting passengers
irrespective of the time of day or sex of the driver, although male drivers
were at greater risk. Driver deaths per 1000 crashes increased for 16- and
17-year-olds transporting male passengers or passengers younger than 30 years.
Conclusion Our data indicate that the risk of fatal injury for a 16- or 17-year-old
driver increases with the number of passengers. This result supports inclusion
of restrictions on carrying passengers in graduated licensing systems for
young drivers.