Background Teens diagnosed with Attention Deficit and Hyperactivity Disorder (ADHD) are involved in higher number of crashes (4 times higher) than non-ADHD teens. However, the specific behavioral factors behind this large discrepancy are largely unknown. Naturalistic driving studies (NDSs) offer a novel solution to obtaining objective measures of teens’ behavior, particularly those teens with ADHD.

Methods A total of 100 teens who received a learner's permit and one of their parents from Southwest Virginia were recruited to participate in this study. Among the 100 participants, 10 were diagnosed with ADHD through reliable clinical assessment procedures and diagnoses. Participant's vehicles were instrumented with data acquisition system (DAS) that collected continuous driving performance data, vehicle data along with audio and video data for 15 to 24 months.

Results Various objective driving measures were collected and this analysis focused on Crashes and Near Crashes (CNC) (measureable physical contact or near contact). Trained data coders have watched videos of CNC to determine the behavioral and environmental factors present 5 seconds prior and 1 sec after the onset of CNC events. This study has collected driving data for 305,185 trips totaling over 35,000 hours of driving. Preliminary coding efforts identified 82 crashes and 114 near-crashes. Analyses indicated that the ADHD teens had higher rates of CNC than their non-ADHD peers (22.6 vs. 11.5; p < 0.03). The data were further analyzed to investigate driver behaviors that may have contributed to the occurrence of CNC events. The ADHD teens have engaged in high-risk secondary tasks, such as texting (7% vs 1% in ADHD vs non-ADHD) and passenger interaction (30% vs 19% in ADHD vs non-ADHD), which have been found to significantly increase the risk of CNC involvement. More in-depth statistical analyses are underway.

Conclusions These results provide corroborating information regarding higher crash rates for ADHD teens as well as further insight into the types of behaviors that ADHD teens are performing that contribute to this heightened crash risk. Identification of the specific driving behaviors that increase crash risks in novice teens, particularly teens with ADHD, will allow for the development of effective countermeasures to reduce and prevent injury in this vulnerable population.