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 0.08%. This standard was established to help regulate alcohol consumption and promote safer driving practices. A BAC of 0.08% indicates that a person's ability to operate a vehicle may be significantly impaired, affecting coordination, judgment, and reaction times.

Setting the limit at this level helps law enforcement to enforce the law more consistently, as 0.08% is widely recognized as a threshold where impairment is likely. Moreover, this limit has been supported by research and public safety campaigns, reflecting a balance between responsible alcohol consumption and the need to keep roadways safe for all users.

Some states might have lower limits for commercial drivers or for drivers under the age of 21, but for the general adult population, 0.08% is the established norm across the majority of states.