Effects of the California graduated driver licensing program.
OBJECTIVE
On July 1, 1998, in an effort to ameliorate the problem of high teenage driver crash rates, California implemented a graduated driver licensing system (GDLS).


METHODS
Data on injury crashes of 16- and 17-year-old drivers from a pre-GDLS year were compared with data from two post-GDLS years. Per-capita crash rate ratios were adjusted for changes in crash rates of 25- to 34-year-old drivers, who were unaffected by the GDLS. Prevented numbers and 95% confidence intervals were estimated.


RESULTS
Fatal or severe injury crash rates were significantly lower during each of the two post-GDLS years (adjusted rate ratios (RR)=0.72 and 0.83, for 2000 vs. 1997 and 2001 vs. 1997, respectively). Significant rate reductions were observed for all crash types, particularly for struck object (RR=0.71 and 0.80, for 2000 vs. 1997 and 2001 vs. 1997, respectively) and non-collision (RR=0.63 and 0.72, for 2000 vs. 1997 and 2001 vs. 1997, respectively). Minor injury crash rates were also lower during post-GDLS years (RR=0.87 and 0.90, for 2000 vs. 1997 and 2001 vs. 1997, respectively). Percent reductions were notably larger during the hours of the late night driving restriction (midnight-5 a.m.) (RR=0.79 and 0.87, for 2000 vs. 1997 and 2001 vs. 1997, respectively).


CONCLUSIONS
The implementation of the California GDLS was followed by large reductions in the rate of injury-producing motor-vehicle crashes.


CONCLUSIONS
This evaluation supports previous evidence that GDLS is an effective countermeasure to adolescent motor-vehicle crashes and their associated injuries. States with a traditional licensing system may prevent adolescent driver crashes by adopting a GDLS. Future studies should examine factors that influence teenager compliance with GDLS provisions and identify approaches to improving compliance.
Southern California Injury Prevention Research Center, University of California, Los Angeles, School of Public Health, 10911 Weyburn Avenue, Suite 200, 90024, USA. tr@ucla.edu
Thomas M
TM
Rice
Corinne
C
Peek-Asa
Jess F
JF
Kraus
D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D000293:Adolescent; D000294:Adolescent Behavior; D017677:Age Distribution; D001334:Automobile Driving / Q000592:standards* / Q000706:statistics & numerical data*; D002140:California / Q000453:epidemiology; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008004:Licensure / Q000592:standards* / Q000706:statistics & numerical data*; D008297:Male; D011159:Population Surveillance; D015995:Prevalence; D017678:Sex Distribution; D014947:Wounds and Injuries / Q000453:epidemiology*