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 limit is established to help ensure safe driving conditions and reduce the risk of accidents caused by impaired driving. At or above this BAC level, an individual is generally considered to be too impaired to operate a vehicle safely. It reflects a standard that balances the need for personal freedom with public safety, taking into account the detrimental effects of alcohol on motor skills, judgment, and reaction times.

The decision to set 0.08% as the legal limit is informed by research indicating that drivers begin to show significant impairment at this level, resulting in a higher likelihood of being involved in an accident. Therefore, authorities enforce this limit to help decrease alcohol-related traffic incidents and enhance overall road safety for all users.