Farmer, Charles M.; Wells, JoAnn K.
Insurance Institute for Highway Safety
The objective of this study was to evaluate the effectiveness of skid avoidance training on traffic citation and crash rates of newly licensed teenage drivers.
Approximately half of all 16-17-year-old students who successfully completed a basic driver education course were offered the opportunity to participate in the skid avoidance and vehicle control course. Of 1,481 students who were offered the skid avoidance course, 1,142 students declined the offer, 105 accepted the offer but failed to schedule or show up for an appointment, and 234 students completed the course. Traffic citation and crash rates over the subsequent 2 years were computed, and the effectiveness of the skid avoidance training was estimated using an intent-to-treat (ITT) paradigm, an instrumental variables (IV) methodology, and a methodology that matched those completing the course to demographically similar subjects without skid training.
The rate of moving violation citations was 25.6 per 100,000 days for drivers who were offered free skid training and 22.4 for drivers who never received the offer, so the ITT relative rate was 1.14 (95% CI 0.96 to 1.35). The IV relative rate was 2.50 (95% CI 0.77 to 8.15) and the matching-based rate was 0.94 (95% CI 0.63 to 1.39). The rate of police-reported crashes was 8.7 for drivers who were offered free skid training and 8.6 for drivers who never received the offer, so the ITT relative rate was 1.01 (95% CI 0.76 to 1.34). The IV relative rate was 1.06 (95% CI 0.15 to 7.59), and the matching-based rate was 0.73 (95% CI 0.38 to 1.39). None of these estimates was statistically significant.
There is no clear evidence from this study that the skid avoidance and vehicle control course improves driver safety. A major problem is that the course does not seem to be appealing to many newly licensed teenage drivers and their parents. When analyses are done that avoid the problems of self- selection into the course, the results are variable, depending on the methodology used. Because of this, there is no unbiased estimate of the effect of completing the course, and it cannot be said that it has no benefit. However, from a public health intervention perspective, it can be said that offering the course does not result in measurable reductions in violations or crash reductions.
This skid avoidance and vehicle control course does not seem to reduce the relatively high crash risks of newly licensed teenage drivers, but it may offer insight into the development of an effective program.