The per-mile accident rate of 16-year-old novices is approximately 10 times that of adults, a difference that has been attributed to the immaturity of youth and the errors of inexperience. Research separating the two influences shows that, over the first few years, the effects of experience greatly exceed those of age, with reductions of approximately two-thirds in the first 500 miles of driving. A study was undertaken to identify the behavioral antecedents of young driver accidents, including any subset of antecedents that could account for the inordinately high initial accident rate. Narrative descriptions of more than 2000 accidents involving 16-19-year-old drivers in two states were analyzed for behavioral contributors. The great majority of non-fatal accidents resulted from errors in attention, visual search, speed relative to conditions, hazard recognition, and emergency maneuvers, with high speeds and patently risky behavior accounting for but a small minority. Differences in the types of errors by first year novices and more experienced youth were relatively few in number and small in magnitude, indicating that the benefits of experience apply rather generally across all aspects of driving.