The teen-age driver.

I: In terms of driver record alone (uncontrolled for Mileage differences), statistical analysis of the data indicated... a accident frequency for both teenage males and females to be unrelated to age. b. violation frequency for both males and females to increase as age increased. II: Order to adequately control the effects of differences in exposure between age groups and to determine the relationship between relative risk and age it was necessary to resort to a multiple regression analysis (See chart V on opposite page). This analysis established: 1) exposure was a more important factor than age in determining accident and violation rates and 2) age was related only to male accident rates wit older males having fewer accidents. III In order to determine the effects of inexperience, immaturity (as measured by age) and parental control on accident and violation records, it was again necessary to resort to a multiple regression analysis. Summarised below are the results of the regression analysis which included all variables. a. For males, addition to two exposure variables which were found to be positively related to accidents, age was found to be positively related to accidents, age was found to be a predictor of accidents, with older males having fewer accidents. From this result, it was concluded that some intrinsic components of age (e.g. immaturity) were factors in the accident frequency of the younger male teenage driver. Male violation frequencies were found to be related to three exposure variables, miles in life (experience) and parental regulations. More experienced drivers and more regulated drivers had more violations. It was concluded that regulations came as a result of violations rather than the converse. Age (immaturity) approached significance, and the direction of the relationship was a positive or increasing one. Some possible explanations of these findings were offered in the text on page 15. b. For females one exposure variable and an experience variable (months license in force) were found to be significantly related to violations- the more experienced female drivers having more violations. Parental regulations and age (immaturity made no contribution to addident or violation records for females. 4. In terms of absolute risk, the authors can find no evidence to support a raise in the minimum licensing age in California. In teens of relative risk, however, there is some evidence, for males, that younger drivers are more predisposed to accidents than drivers in their older teens. Any final decision concerning a raise in licensing age must be based upon the relative merits of these two methods of comparison. 5. The sample of teen-ages drivers was broken into three groups (did take, didn't take and couldn't take) on the basis of their answer to the questionnaire item regarding the completion of a behind the wheel driver training course. When the three groups were compared, the trained group had fewer violations, but no significant differences were found between the trained and untrained groups on accidents. Although is entirely possible that some programs in certain individual school districts are effective, this finding raises serious questions about the general effectiveness of state-wide driver training in reducing accidents.