This thesis has evaluated the effectiveness of GDL programs both in New Jersey and across the United States using several metrics. The New Jersey GDL program was analyzed because it is considered one of the most stringent programs in the country. It was found that GDL indeed reduces the per capita rate of crashes for teen drivers in New Jersey. However, no statistical difference was seen in the rate of fatalities in teen driver crashes. The per capita rate of violations for 16 and 17 year old drivers was lower after GDL, but the rate of point-carrying violations increased for 19 and 20 year old drivers who were licensed under GDL. The September, 2008 directive by the New Jersey Attorney General banning plea-agreements for teens significantly reduced the rate of violations further for 16 and 17 year old GDL drivers. The factors that led to teen crashes did not change in the United States after GDL. Teen drivers are still prone to distractions and inappropriate behavior while driving. Teen drivers also have higher rates of control loss and road departure crashes when compared to adults. Finally, it was found changes in the number teen driver crashes and fatalities are associated with similar changes in travel exposure. Teen crashes and fatalities have dropped with the implementation of GDL but teen VMT has also dropped. Graduated driver's licensing did not change the reasons for teen driver crashes. Also, it is likely that any reductions in the number of teen crashes or fatalities are associated with reductions in exposure and not changes in teen driver behavior. / Ph. D.