O2020: Using a Novel Smartphone Telematic App to Measure Adolescent Driving Behaviors

Background: Motor vehicle crashes are a leading cause of adolescent death and disability. Risky driving behaviors are associated with adolescent motor vehicle crashes. We report preliminary data for risky driving behaviors in adolescent drivers using a smartphone application.

Methods: Prospective data was collected using Way to Drive, a novel research smartphone application developed by TrueMotion-Cambridge Mobile Telematics and managed by University of Pennsylvania. Licensed Pennsylvania drivers aged 16-18 years downloaded Way to Drive. For this analysis, we used the first eight weeks of data of drivers with a minimum of 50 trips to describe trip-level variation in metrics passively collected by the app: trip duration and length, nighttime driving (11pm-5am), hard braking and acceleration events (kinematic risky driving, KRD), speeding, and handheld cellphone use while driving. Zero-inflated Poisson modeling clustered by driver was used to evaluate sex-specific differences across these metrics.

Results: Seventy-Nine adolescent drivers (28% male; 85% white) had a mean age of 17.4 (sd ±.005) years, with a mean licensure length of 8.0 (sd ±.06) months. They recorded 11,342 unique trips, totaling 69,780 miles and 3010 hours. Adolescents drove a mean of 185 trips at 6.2 miles/trip and 15.9 minutes/trip. There was little nighttime driving (1.6% of trips). KRD events occurred in 55.9% of trips at a rate of 26.5 events/100 miles. Speeding occurred in 37.3% of trips (mean duration of 9.7 minutes/100 miles). Handheld phone use was detected in 28.9% of trips (mean duration of use 16.8 minutes/100 miles). Handheld phone use while speeding occurred in 5.2% of trips (mean duration of 54.6 seconds/100 miles). Compared to females, males had increased incidence of KRD events while driving IRR=1.58 (1.12-2.24 p<.05); KRD events with active cellphone use IRR=2.65 (1.36-5.14 p<.01); and take a nighttime trip IRR=2.96 (1.76-4.96 p<.01). There were no significant differences in minutes of active cellphone use, speeding duration, speeding with active cellphone use by sex.

Conclusion: Adolescent drivers engage in risky driving behaviors. Way to Drive gives insight into normally difficult to measure teen driving behaviors. Variations in risky driving behaviors in this sample highlight opportunities for targeted interventions on risky driving behaviors. Future research can examine relationships among spatial and temporal characteristics of driving and cellphone use, to target risky behaviors that increase risk for a motor vehicle crash.