As of this writing (in mid 2021), the NHTSA website contains a webpage about “Drunk Driving”, which features a table entitled “The Effects of Blood Alcohol Concentration”. Table 8 reproduces this table, nearly verbatim, in compliance with the “Terms of Use” of the website. The table shows, as a function of the level of blood alcohol concentration (BAC) (in g/dL), (1) the typical effects, independently of any task, and (2) the predictable effects for the specific task of driving.
| BAC (in g/dL) | Typical effects | Predictable effects on driving |
| 0.02 | 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) |
| 0.05 | 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 |
| 0.08 | 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 |
| 0.10 | Clear deterioration of reaction time and control, slurred speech, poor coordination, and slowed thinking | Reduced ability to maintain lane position and brake appropriately |
| 0.15 | 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 |