What is the legal blood alcohol concentration (BAC) limit for drivers over 21 in most states?

The legal blood alcohol concentration (BAC) limit for drivers over 21 in most states is set at 0.08%. This standard is established to help reduce the risk of impaired driving and enhance roadway safety. When a driver's BAC reaches this threshold, they are considered legally impaired, meaning their ability to operate a vehicle is compromised. This limit has been widely adopted across the United States as a unified measure to enforce drunk driving laws, with the aim of deterring individuals from consuming alcohol before driving. By maintaining a clear standard, law enforcement can more effectively manage and investigate suspected instances of impaired driving, ultimately leading to safer roads.

BAC levels lower than this limit may still lead to impaired driving consequences depending on individual circumstances, but 0.08% is the definitive legal threshold for most adult drivers.