Table 1.

Coded dimensions in 20-second segments from each video clip in three domains of interest

Domain	Dimension	Examples
Safety	Errors	Running stop signs/lights, other traffic sign violations, turn errors, lane keeping, accelerating or braking hard enough to exceed .35 g’s (lateral, vertical, and/or longitudinal)
Driver State	Distraction	Included several categories, e.g. talking, singing, dancing, eating/drinking, tending to personal hygiene (hair, teeth), cell-phone, etc.
	Sleepiness	Slow eye lid closure, fixed gaze, rubbing eyes, yawning, low facial and bodily muscle tone, leaning/holding neck/head
Gaze Movements	Presence/absence of both driving (e.g. mirrors) and non-driving related gaze movements (e.g. reaching for something)
Exposure
Weather	Visibility	Reduced visibility due to fog, smoke or precipitation
	Precipitation	Any precipitation that causes the wipers to be used
	Road Condition	Potentially slippery roads (due to snow, ice or otherwise wet)
	Light-level	Non-day light or diminished light levels
Road Culture	City	multi-lane, single lane city streets, etc.
	Rural	rural highways, gravel roads, etc.
	Highway	interstate, shoulder present/absent highways, entrance/exit ramps, etc.
	Intersection	Sign or light controlled and uncontrolled intersections