Blood Alcohol Concentration (BAC) in g/dL 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 in necessary visual and auditory information processing