Maryland DUI Laws

§ 21-902. Driving while under the influence of alcohol, while under the influence of alcohol per se, while impaired by alcohol, or while impaired by a drug, a combination of drugs, a combination of one or more drugs and alcohol, or while impaired by a controlled dangerous substance.

(a)  Driving while under the influence of alcohol or under the influence of alcohol per se.-

(1) A person may not drive or attempt to drive any vehicle while under the influence of alcohol.

(2) A person may not drive or attempt to drive any vehicle while the person is under the influence of alcohol per se.

(3) A person may not violate paragraph (1) or (2) of this subsection while transporting a minor.

(b)  Driving while impaired by alcohol.-

(1) A person may not drive or attempt to drive any vehicle while impaired by alcohol.

(2) A person may not violate paragraph (1) of this subsection while transporting a minor.

(c)  Driving while impaired by drugs or drugs and alcohol.-

(1) A person may not drive or attempt to drive any vehicle while he is so far impaired by any drug, any combination of drugs, or a combination of one or more drugs and alcohol that he cannot drive a vehicle safely.

(2) It is not a defense to any charge of violating this subsection that the person charged is or was entitled under the laws of this State to use the drug, combination of drugs, or combination of one or more drugs and alcohol, unless the person was unaware that the drug or combination would make the person incapable of safely driving a vehicle.

(3) A person may not violate paragraph (1) or (2) of this subsection while transporting a minor.

(d)  Driving while impaired by controlled dangerous substance.-

(1) A person may not drive or attempt to drive any vehicle while the person is impaired by any controlled dangerous substance, as that term is defined in § 5-101 of the Criminal Law Article, if the person is not entitled to use the controlled dangerous substance under the laws of this State.

(2) A person may not violate paragraph (1) of this subsection while transporting a minor.

(e)  Crime committed in another jurisdiction.- For purposes of the application of subsequent offender penalties under § 27-101 of this article, a conviction for a crime committed in another state or federal jurisdiction that, if committed in this State, would constitute a violation of subsection (a), (b), (c), or (d) of this section shall be considered a violation of subsection (a), (b), (c), or (d) of this section.

[An. Code 1957, art. 661/2, § 11-902; 1977, ch. 14, § 2; 1980, ch. 144; 1981, ch. 242; 1988, ch. 562; 1993, ch. 308; 1995, ch. 498; 1996, ch. 652, § 2; 1997, ch. 451; 1999, ch. 347; 2001, chs. 4, 5, 483; 2002, ch. 213, § 6; 2003, chs. 243, 244, 246; 2004, ch. 335; 2005, chs. 482, 495, 496.]

§ 11-103.2. Alcohol concentration.

(a)  Alcohol concentration.- "Alcohol concentration" means:

(1) The number of grams of alcohol per 100 milliliters of blood; or

(2) The number of grams of alcohol per 210 liters of breath.

(b)  Measurements.- If the alcohol concentration is indicated in the number of milligrams of alcohol per deciliter of blood or the number of milligrams of alcohol per 100 milliliters of blood, a court or an administrative law judge, as the case may be, shall convert the measurement into the number of grams of alcohol per 100 milliliters of blood by dividing the measurement by 1000. 

§ 11-103.1. Alcohol.

"Alcohol" means any substance or substances containing any form of alcohol, including ethanol, methanol, propynol, and isopropynol.