Multiple speakers will present their results from recent studies investigating novel teen interventions. Additionally, an international perspective on recent teen driver research will be provided.
Evaluation of an Advanced Driver Training Program for Young Traffic Offenders
Robert D. Foss, UNC Highway Safety Research CenterShow Abstract
Yudan Wang, University of North Carolina, Chapel Hill
Natalie O'Brien, University of North Carolina, Chapel Hill
Arthur Goodwin, University of North Carolina, Chapel Hill
Stephanie Harrell, UNC Highway Safety Research Center
Advanced driver training programs are a broadly popular approach to improve young driver safety in the U.S. Typically offered by auto manufacturers, law enforcement officers, professional race car teams and amateur auto enthusiast clubs, these programs provide behind-the-wheel experiences in controlled settings that are thought by parents, teens and others to be highly valuable. However, none of these programs have been carefully evaluated. We randomly assigned 599 young drivers who had received a traffic citation to one such program, or a control condition involving traditional classroom traffic safety education. Time-to-event (survival) analyses of participants’ subsequent crash experience over the course of 550 days revealed no meaningful difference in time to a crash for those who participated in the experimental or control courses, or those who failed to complete either. A strength of the study was the random assignment of participants to conditions, ruling out self-selection bias. However, traffic offenders presented a severe challenge for a training program as this group had already developed a higher risk driving demeanor than is the case in the broader population of young drivers. Additional research on a population of drivers who are earlier in their driving careers and have not yet developed a risky driving orientation, with a similarly strong experimental design, is urgently needed to inform traffic safety practitioners and parents about the potential value of such hands-on programs.
Influence of Family Communication Patterns on Teen Risky Driving and Driving Intervention Effectiveness
Cara Hamann, University of IowaShow Abstract
Laura Schwab-Reese, Purdue University
Elizabeth O'Neal, University of Iowa
Brandon Butcher, University of Iowa
Corinne Peek-Asa, University of Iowa
Teen drivers are at heightened crash risk, largely due to lack of experience. Parents play a key role in influencing their teen’s behaviors and attitudes around driving safety. Parent-involved interventions have been shown to improve teen driving safety, but these interventions tend to be resource intensive and have limited scalability. This study aimed to determine the impact of family communication patterns on teen risky driving and on teen driving intervention effectiveness. Results showed that teen risky driving at baseline did not vary by family communication patterns. Findings also showed that the impact of a teen driving intervention was stronger among families with laissez-faire family communication style, which is characterized by little focus on child conformity and downplayed communication. These results provide a framework for targeting high-resource teen driving interventions (event recorder feedback and parent-communication training) to families with certain communication characteristics in order to attain the greatest risk reductions.
Computational Cognitive Modeling of Intervention Effects on Adolescent Drivers’ Crash Risk
Jessica Hafetz Mirman, University of Alabama, BirminghamShow Abstract
Allison Curry, Children's Hospital of Philadelphia
Daniel Mirman, University of Alabama, Birmingham
Background: The etiology of risky driving behavior among adolescents is of great interest to transportation scientists, yet existing explanatory frameworks of within-person changes in crash risk are underdeveloped. Population-level crash rates incrementally decrease following licensure, in a power-law pattern, which has led to speculation that recently licensed teen drivers’ crash risk also decreases incrementally as they accrue experience. However, it cannot be assumed that individual-level changes in crash risk mirror the population-level changes in crash rates. In statistics, this is known as an ecological fallacy and in formal logic it is known as the fallacy of division, a type of category error. Further, Myung et al., 2000 demonstrated that a power-law “artifact” can occur when data from non-linear models are arithmetically averaged in the presence of individual difference factors.1 Previously we demonstrated that aggregating individual-level abrupt decreases in crash risk accurately fits population-level crash rate data from over 1 million adolescents, thus demonstrating that the power-law artifact can be present in teen drivers’ crash data.2 To address the lack of explanatory frameworks that specify why population-level crash rates change so dramatically during the initial months of licensure and to contribute to the growing body of literature relating to the power-law artifact as it is observed in the context of insight, learning, and skilled performance3–5 we used a computational cognitive modeling approach6 to define a phase transition framework specific to the teen driver. The central principles of the computational model were: (1) transitioning from a riskier novice driver to a safer (less novice) driver can be accomplished through a series of phase transitions due to adopting new strategies, with abrupt transitions happening at different times for different adolescents and (2) interventions can cause an immediate phase transition as well as increase the likelihood of a future transition. In this report we demonstrate how this phase transition model accounts for effects of two interventions found to reduce police-reported MVCs (ODA, Mirman et al., 2018 and RAPT, Thomas et al., 2016).7,8 These effects are inconsistent with an incremental model of crash risk reduction predicated on the accrual of post-license experience. Methods: We used computational cognitive modeling to develop an individual-level account of the data from two US-based intervention trials administered to teens prior to the accumulation of any post-licensure driving experience and that used police-reported crashes as the main outcome. The phase transition model was defined mathematically using a sigmoid function, which produces a value between 0 (lowest possible risk state) and 1 (highest possible risk state), and a relatively rapid transition from the high-risk state to the low-risk state. Critically, the timing of that transition was assumed to differ across individuals and to be expedited or induced by the interventions of interest. Crash events were simulated based on binomial sampling from the individual crash risk curves. Results: Results of the RAPT simulation illustrate the phase transition model’s strong fit to the data (Fig1). A modest (10%) increase in phase transition probability can translate into a substantial reduction in crash rate, consistent with the observed trial data. The ODA simulation results were highly similar. Discussion: Our model reflected a possible key difference between how the ODA and RAPT may have affected phase transition timing: inducing immediate phase transitions (RAPT) and increasing the probability of a phase transition (ODA). Results suggest that researchers should consider cognitive change processes that beget translational transformations in crash risk trajectories (i.e., shifting crash risk curves) instead of thinking primarily about learning rates and the relationship between accruing experience and crash reduction. Strategy acquisition is one such process. More detail about how to use the computational cognitive modeling approach to evaluate interventions and theories for teen drivers will be provided in our presentation.
Challenging our assumptions: a consideration of selected recent evidence from young and novice driver research
Neale Kinnear, Transport Research Laboratory, Ltd. (TRL)Show Abstract
This talk seeks to present selected results from recent studies that offer an opportunity to challenge current assumptions and prompt discussion.