Fatigued drivers have twice the percent of for speeding and going the wrong way.
Fatigued drivers have a seven times higher percent for crossing the center line than all human factors. Drivers who drink have a four times higher percent for speeding than all other factors. Drivers on illegal medication have a five times higher percent for wrong way direction. There are no significant weather effects for human factor related drivers. Fatigue has a three times higher percent for headons, and a seven times higher percent for overturns.