Final answer:
Driving under the influence (DUI) involves operating a vehicle while affected by alcohol or psychoactive drugs. The legal BAC limit is generally 0.08% in the U.S., and factors like age and health can impact intoxication levels. DUI is a critical public safety issue, leading to advocacy by organizations such as MADD.
Step-by-step explanation:
Driving under the influence (DUI) refers to operating a motor vehicle under the influence of or affected by alcohol or other psychoactive drugs. DUI is a serious offense because alcohol and other substances can significantly impair one's judgment and motor skills, making driving unsafe. The legal limit for blood alcohol concentration (BAC) in most U.S. states is 0.08% by volume. However, this limit can be lower for commercial drivers and drivers under the age of 21.
Alcohol, a depressant, can lead to various levels of intoxication, which are measured by BAC. The immediate effect of alcohol and the associated risks are influenced by factors such as age, sex, health condition, and the amount of alcohol consumed. Another contributing factor to DUI cases is the influence of illegal or psychoactive drugs, which can drastically alter an individual's ability to operate a vehicle safely.