Seventy-eight percent of crashes are estimated to involve driver inattention. Of these crashes, many are related to drivers who distract themselves by attempting to multitask. The graph below shows the various multitasking activities that commonly distract drivers before a crash.
Multitasking generally impairs performance at each individual task. Drivers cannot look in two places at once, and thus shift their gaze and attention back and forth between one task and the other. As a consequence, a driver is more likely to misdial their cell phone and insufficiently scan the roadway for hazards when attempting both tasks simultaneously.
Where a driver looks, and thus, where a driver attends, can be recorded with an eye-tracker. Eye-trackers are special devices either worn by drivers or composed of cameras mounted across the dashboard. Human factors scientists use eye-trackers to record both a driver’s field of view and where in that field of view the driver is looking.
The figure below shows a series of frames from a movie recorded by an eye-tracker while a driver was adjusting the radio. The red cross-hair indicates where the driver was looking in each frame. In the first frame, on the left, the driver looks to a car in the distance. After looking back and forth between the radio and the road for 1.3 seconds, the oncoming car is now passing the driver (it can be seen on the extreme left side of the last frame on the right). If the oncoming vehicle had crossed the centerline while the driver was adjusting the radio, multi-tasking may have resulted in a fatally delayed response.
Some people claim themselves to be good multitaskers; however, a “good” multitasker may not be aware of what they are missing. Drivers directing their attention towards a non-driving task may be blissfully unaware of the collisions they narrowly avoided. Out of sight, out of mind.
For more information on distracted driving please see our recent article on Visual Attention in Vehicle Accidents.
 Dingus, T A, Klauer, S G, Neale, V L, Petersen, A, Lee, S E, Sudweeks, J D, Perez, M A, Hankey, J, Ramsey, D J, Gupta, S, Bucher, C, Doerzaph, Z R, Jermeland, J, Knipling, R R (2006) The 100-Car Naturalistic Driving Study, Phase II - Results of the 100-Car Field Experiment. (Contract No. DTNH22-00-C-07007). Washington, DC: National Highway Traffic Safety Administration.