At what BAC level is it typically illegal to drive in most states?

The legal blood alcohol concentration (BAC) level for driving is typically set at 0.08 in most states across the United States. This standard is based on research that indicates this level of impairment significantly affects motor skills, judgment, and reaction times, which are critical for safe driving. At a BAC of 0.08, a driver's ability to operate a vehicle is noticeably compromised, increasing the likelihood of accidents.

Most states have adopted this threshold to create a clear and enforceable standard for law enforcement and to promote public safety. Furthermore, penalties for driving over this limit are often severe, including fines, license suspension, and possible jail time, underscoring the importance of adhering to this legal BAC limit.

Other BAC levels listed, such as 0.05, 0.10, and 0.12, are either less effective at enforcing safe driving or pertain to different contexts or lesser degrees of impairment according to various state laws, but the 0.08 standard is the most widely recognized and enforced for determining legal intoxication while driving.