Kentucky's current GDL program, which applies to drivers up to age 18, was enacted in 1996. The program includes a six-month instruction permit for drivers under age 18 (minimum age 16), a restriction on driving between midnight and 6am and a requirement for adult-supervised driving for permit drivers. In addition, there is a six-point limit on traffic violations with a penalty of license suspension for drivers under age 18, a requirement for a four-hour driving safety education class (or driver education course) and a 0.02 ml/dl limit on blood alcohol concentration (continues up to age 21 ).

Objectives: The objectives of this program evaluation were: (a) to examine teen driver motor vehicle crashes, crash-related injuries, and crash-related costs before and after the implementation of the GDL program; (b) to examine the implementation of the program at the local level ; and (c) to recommend actions to enhance the program's effectiveness in addressing the teen crash problem.

Methods: Crash and licensing data before ( 1993-1995) and after GDL ( 1997-2000) were analyzed. Data on miles driven were obtained from driving logs of over I ,000 high school students. Estimation of the cost of crashes was derived from analysis of crash data using the Crash Cost computer software program. Information on local implementation of GDL was obtained through interviews and through a questionnaire survey of 700 law enforcement officers and over 40 district judges.

Results: Results indicate a 31 percent reduction in crashes for 16 year-old drivers after the GDL program, and a similar reduction in fatal crashes (31 percent) and injury crashes (33 percent), crashes between midnight and 6am (36 percent), and alcohol-related crashes (32 percent). Cost analysis indicates an estimated reduction of $36 million per year in 16 year-old teen driver crash-related expenses. Results indicate that this is due to the 83% reduction in the number of 16 to 16 1/2 year-old drivers involved in crashes. However, the number of crashes has not been reduced for drivers over age 16 1/2, i.e. drivers who may be past the permit level. In addition, the six-point limit on traffic violations and the non-cumulative penalties on 0.02 blood alcohol limit violations have not reduced the number of traffic violations or alcohol-related crashes for teen drivers over age 16 1/2.

Recommendations: The six-month permit level has been successful in substantially reducing crash-related injuries and fatalities and should be retained. Additional measures, such as upgrading to an expanded GDL program, are needed to reduce crash-related injuries and fatalities for 16 1/2 to 18 year-old drivers. Specific recommendation are made to increase parental awareness and enforcement of program provisions.

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The contents of this report reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the University of Kentucky, the State of Kentucky, or the National Highway Traffic Safety Administration. This report does not constitute a standard, specification, or regulation.