Blood Alcohol Concentration (BAC)*
|
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
|
*Information in this table shows the BAC level at which the effect usually is first observed, and has been gathered from a variety of sources including the National Highway Traffic Safety Administration, the National Institute on Alcohol Abuse and Alcoholism, the American Medical Association, the National Commission Against Drunk Driving, and http://www.webMD.com.
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