What are illegal per se laws?
An illegal per se law makes it illegal in and of itself to drive with an alcohol concentration measured at or above the established legal level. Forty-eight states and the District of Columbia have established a per se law. The legal limit in most states is .08 blood alcohol concentration (BAC) per se. That means it is against the law to drive a motor vehicle if you have a BAC of .08 or more, without having to prove intoxication.