Contribution of Cell Phone Use and Other Secondary Tasks to Crashes and Near Crashes Among Adult and Teenage Drivers

Background/Purpose. Driver inattention is a major cause of motor vehicle crashes and an increasing national concern. While adult driver distraction has been widely assessed, less is known about teenage driver distraction, despite their high crash risk. The purpose of this research was to examine crash risk due to secondary task engagement.

Methods. The vehicles of 42 newly licensed teenage drivers were instrumented with accelerometers, cameras, global positioning systems, and other measures, allowing objective assessment of crashes and near crashes and secondary task engagement. Case control methods were employed comparing the frequency with which a secondary task was present in a crash or near crash compared to a sample of non-crash driving matched to crash driving conditions. Odds ratios were calculated comparing secondary task engagement for teen drivers.

Results. Cell phone dialing (OR=5.95) and locating/answering/managing (OR= 4.68), texting (OR= 3.26), and reaching for objects (OR =4.99) were the distracting tasks associated with the highest crash/near-crash risks for teenage drivers.

Conclusions. Secondary tasks, particularly those that require drivers to take eyes off the road, contribute significantly to teenage crashes and near-crashes and were higher than for adult drivers assessed in a previous study. Notably, cell phone dialing increased risk, but talking on a cell phone did not. The findings have implications for public policy and related countermeasures regarding secondary task engagement and motor vehicle crashes among teenage drivers.