The fatal crash rate for 16-year-old drivers declined sharply after states began enacting graduated licensing laws in the 1990s, a new Insurance Institute for Highway Safety (IIHS) study found.
Fatal crash involvements based on the population of 16-year-old drivers fell 26 percent during 1993-2003, the study found.
The overall number of 16-year-old drivers in fatal crashes decreased from 1,084 in 1993 to 938 in 2003, while during the same period there was an 18 percent increase in the 16-year-old population.
Licensing of 16-year-old drivers and fatal crash rates involving 16-year-old drivers
Percentage of 16 year-olds licensed
Fatal crashes per 100,000 population
"This isn't a study of graduated licensing per se. It's a look at the status of 16 year-olds in states both with and without graduated licensing," said Susan Ferguson, the Institute's senior vice president for research. "Still, this study does reveal some very positive effects of the new licensing systems. The main reason for the decline in the crash rate is that fewer beginning drivers are getting their licenses when they turn 16."
While the population-based ratio of fatal crash involvements declined, the 2003 rate based on the number of licensed drivers didn't change compared with the 1993 rate. Seventy-three 16-year-old drivers per 100,000 license holders were in fatal crashes in 1993. This compares with 74 per 100,000 in 2003.
"In time we do expect to see a drop in the fatal crash rates per licensed 16-year-old driver," Ferguson said.
Teenagers have the highest crash risk of any age group about four times higher than for older drivers. Teenagers are more likely than older drivers to be in crashes involving driver error and speeding.
"The riskiest time for teens is when they first start driving," Ferguson said. "The key to the effectiveness of graduated licensing is that it phases in a driver's license over time, keeping teens in the learner phase longer and delaying a full-privilege license until beginners are older, more mature, and more experienced."
An important finding of the new Institute study is that restrictions on 16 year-olds did not simply shift the crash risk to older teens. Crash rates dropped 11 percent for 17 year-olds and 6 percent for 18-19 year-olds.
One of the most dangerous scenarios is when a teenage driver transports other teens and, on a per capita basis, this kind of crash declined 39 percent during 1993-2003. Meanwhile, most other characteristics of 16 year-olds' crashes stayed the same over time.
Estimated crash reductions in selected jurisdictions with graduated licensing
A full graduated licensing law has three stages. Beginners must remain in each of the first two stages for minimum time periods: supervised learner's period; intermediate license (after the driver's test is passed) limiting unsupervised driving in highrisk situations; and then a license with full privileges available after completing the first two stages. Key elements of the intermediate stage include limits on unsupervised driving at night and transporting teenage passengers. Certification by parents that a learner has driven a minimum number of supervised hours also is important.