UNC researchers show passengers boost risk of young driver accidents

Press Release - For immediate use

May 16, 2002

UNC News Services

CHAPEL HILL — Last year, a University of North Carolina at Chapel Hill study showed that the state's graduated driver licensing (GDL) system, which delays full driving privileges for the youngest drivers until they gain substantial behind-the-wheel experience, dramatically cut the number of crashes, injuries and deaths among such drivers.

Now, analyses of additional data reveal that when 16- and 17-year-old drivers transport passengers, their risk of a fatal or injury-causing crash grows significantly.

"We found that when a young driver carries one passenger, the risk of such a crash is somewhat higher - about 33 percent," said Dr. Robert D. Foss, research scientist at the UNC Highway Safety Research Center. "The real concern is multiple passengers. Two passengers more than double the risk — a 137 percent jump — and three or more have a similar effect, increasing crash risk by 127 percent compared with having no passengers."

Amending the N.C. GDL system to limit the number of passengers riding with young provisional drivers, as several states have done, should reduce crashes further, Foss said.

"Limiting Level 2 drivers to carrying one passenger younger than 21 would likely achieve most of the benefit available from a passenger restriction," he said. "A one-passenger limit would affect a small proportion of teen drivers' trips since currently, 89 percent of trips by these drivers involve either one or zero passengers. However, trips that the limit would prevent are the most risky ones."

Foss and center colleagues conducted their analyses at the request of state Sen. Austin Allran of Hickory and state Rep. Debby Clary of Cherryville, sponsors of a bill to limit passengers riding with novice drivers. They worry too many teens still die on N.C. highways when driving or riding with friends in cars.

"The three-stage N.C. graduated driver licensing system for beginning drivers was implemented on Dec. 1, 1997, and became the second such system in the United States," Foss said. "Since that time, at least 32 other states and the District of Columbia have enacted GDL systems. In view of recent research findings, many of the newer GDL systems either prohibit or limit passengers, but North Carolina's does not."

The UNC Highway Safety Research Center released the new analyses today (May 16) to coincide with kickoff of the statewide "Click It or Ticket" Campaign in Hickory's Winkler Park.

Nineteen states now include a restriction on carrying passengers for drivers with an intermediate license. Ten prohibit any passengers, while six allow only one, Foss said. Most such restrictions apply during the first six months that unsupervised driving is permitted, which corresponds to the N.C. Level 2 license.

A study published in the Journal of the American Medical Association in 2000 showed that the increased risk of driver death among 16- and 17-year-old drivers with one passenger was 39 percent and 48 percent, respectively. Among those carrying two passengers, the risk jumped to 85 percent and 158 percent, respectively.

"That study also showed that with three passengers, a 16-year-old driver's risk increased 182 percent, and a 17-year-old's risk more than tripled -- 207 percent," Foss said.


Note: Foss can be reached at (919) 962-8702 or rob_foss@unc.edu.

N.C. Dept. of Transportation Contact: Jill Warren Lucas, (919) 733-3083

UNC Highway Safety Research Center Contact: Shannon Walters, (919) 962-7803

UNC News Services Contact: David Williamson, (919) 962-8596 or david_williamson@unc.edu

For more information on HSRC's research on graduated driver licensing, click here.

Media Contacts

Caroline Dickson

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