Table 1.

Definition of Secondary Tasks

Secondary Task	Definition
Any secondary task involvement	Presence of any secondary task (including those tasks not summarized here)
Interacting with a passenger in adjacent seat	Interacting with a passenger in adjacent seat
Other external distraction, not otherwise specified	Other external distraction (eg, a nondriving-related glance to look out into a field, look at oncoming traffic on a road with a wide dividing median, look out a window when there are many possible targets for that glance, such as in a busy business district)
Talking or singing	Talking or singing
Other glances into the interior of the vehicle, not otherwise specified	Other nonspecific internal eye glance (eg, a nondriving-related glance to look in the direction of the cup holder area, look down towards the lap, look towards the center stack with no surrounding context as to what specifically is the target)
Cell phone use	Browsing cell phone, dialing hand-held, dialing hand-held using quick keys, dialing hands-free using voice-activated software, holding cell phone, locating/reaching/answering cell phone, other cell phone use, talking/listening to hand-held cell phone, talking/listening to hands-free cell phone, texting
Number of tasks	Sum the number of tasks (including those tasks not summarized here)