Tenn. Code Ann. § 55-10-401: Driving under the influence prohibited - Alcohol concentration in blood or breath

It is unlawful for any person to drive or to be in physical control of any automobile or other motor driven vehicle on any of the public roads and highways of the state, or on any streets or alleys, or while on the premises of any shopping center, trailer park, or apartment house complex, or any other premises that is generally frequented by the public at large, while:

(1) Under the influence of any intoxicant, marijuana, controlled substance, controlled substance analogue, drug, substance affecting the central nervous system, or combination thereof that impairs the driver's ability to safely operate a motor vehicle by depriving the driver of the clearness of mind and control of oneself that the driver would otherwise possess;

(2) The alcohol concentration in the person's blood or breath is eight-hundredths of one percent (0.08%) or more; or

(3) With a blood alcohol concentration of four-hundredths of one percent (0.04%) or more and the vehicle is a commercial motor vehicle as defined in § 55-50-102 .