AZ DPS

Driver Fatigue

Fatigue ChartOverview

What is fatigue? Fatigue is a complex state characterized by a lack of alertness and reduced mental and physical performance, often accompanied by drowsiness.

The Department of Public Safety is committed to reducing collisions caused by fatigued drivers.

Fatigue Signs & Symptoms

  • Forgetfulness
  • Poor Communication
  • Impaired decision making skills
  • Lack of alertness
  • Nodding off
  • Slow reaction time
  • Micro sleep
  • Withdrawn
  • Depressed
  • Moody
  • Quick to anger
  • No sense of humor
  • Lack of interest
  • Always tired

EyeFactors that Cause Fatigue

  • Sleep loss and/or disturbed sleep
  • Disrupted biological clock
  • Excessive physical activity
  • Excessive mental or cognitive work
  • Monotony or familiarity
  • Quality & quantity of sleep
  • Continuous hours of being awake
  • Illness
  • Time of day/circadian effects
  • Sleep disorders
  • Environmental
  • Nutrition
  • Physical fitness
  • Drugs
  • Health
  • Age

Accumulating a Sleep Debt

Sleep loss is cumulative and builds a debt. Most people get 1 to 1.5 hours less sleep per night than they need. People whose sleep was restricted 4 to 5 hours per night for one week needed two full nights sleep to recover vigilance, performance and normal mood. How do you get out of sleep debt? Sleep!

Sleep is a vital need. One-third of our life should be spent asleep. The average person needs at least 8 hours of sleep. Some people mistakenly feel they don't need a full night's sleep.

Create an Optimal Sleep Environment

  • A great pillow and mattress
  • Location of bedroom
  • Cool room temperature
  • NO light
  • Quite
  • White Noise
  • Consistent bedtime routine
  • Security
  • Don't go to bed hungry
  • Avoid work or worry in the bedroom
  • One long period of sleep
  • Consistent wake up time
  • Limit both caffeine and alcohol

Make up for prior loss or disturbance using 1 1/2 - 3 hour sleep periods. Prevent or minimize sleepiness during work especially on night shifts by using 20-30 minute naps or "siesta sleep".

Driving Drowsy

  • 19 hours without sleep is similar to a BAC of .05%
  • 24 hours without sleep is similar to a BAC of .10%