Blood Alcohol Concentration and What it Does

Blood Alcohol Concentration (g/dL)1


Typical Effects


Predictable Effects on Driving

.02


• Some loss of judgment
• Relaxation
• Slight body warmth
• Altered mood


• Decline in visual functions (rapid tracking of a moving target)
• Decline in ability to perform two tasks at the same time (divided attention)

.05


• Exaggerated behavior
• May have loss of small-muscle control (e.g., focusing your eyes)
• Impaired judgment
• Usually good feeling
• Lowered alertness
• Release of inhibition


• Reduced coordination
• Reduced ability to track moving objects
• Difficulty steering
• Reduced response to emergency driving situations

.08


• Muscle coordination becomes poor (e.g., balance, speech, vision, reaction time, and hearing)
• Harder to detect danger
• Judgment, self-control, reasoning, and memory are impaired


• Concentration
• Short-term memory loss
• Speed control
• Reduced information processing capability (e.g., signal detection, visual search)
• Impaired perception

.10


• Clear deterioration of reaction time and control
• Slurred speech, poor coordination, and slowed thinking


• Reduced ability to maintain lane position and brake appropriately

.15


• Far less muscle control than normal
• Vomiting may occur (unless this level is reached slowly or a person has developed a tolerance for alcohol)
• Major loss of balance


• Substantial impairment in vehicle control, attention to driving task, and visual and auditory information proces