Diversion of attention away from activities critical for safe driving toward a competing activity.
"Considerable policy attention that has been directed toward young drivers has primarily resulted in graduated driver licensing. Graduated licensing has been adopted in all 50 states, but there is considerable variation in these state programs. Our finding of the association of several secondary tasks with a significantly increased risk of a crash or near-crash among young drivers provides support for policies limiting the performance of these tasks through graduated licensing requirements or other policy initiatives."
"In conclusion, our findings indicate that secondary tasks requiring drivers to look away from the road ahead, such as dialing and texting, are significant risk factors for crashes and near-crashes, particularly among novice drivers."
Excerpted from: Distracted Driving and Risk of Road Crashes among Novice and Experienced Drivers, by Sheila G. Klauer, Ph.D., Feng Guo, Ph.D., Bruce G. Simons-Morton, Ed.D., M.P.H., Marie Claude Ouimet, Ph.D., Suzanne E. Lee, Ph.D., and Thomas A. Dingus, Ph.D., New England Journal of Medicine, Jan. 2014.