Section 1201 - Operating vehicle under the influence of alcohol or other substance; criminal refusal; enhanced penalty for BAC of 0.16 or more(a) A person shall not operate, attempt to operate, or be in actual physical control of any vehicle on a highway:(1) when the person's alcohol concentration is:(B) 0.02 or more if the person is operating a school bus as defined in subdivision 4(34) of this title; or(C) 0.04 or more if the person is operating a commercial vehicle as defined in subdivision 4103(4) of this title; or(2) when the person is under the influence of alcohol; or(3) when the person is under the influence of any other drug or under the combined influence of alcohol and any other drug.(b) A person who has previously been convicted of a violation of this section shall not operate, attempt to operate, or be in actual physical control of any vehicle on a highway and refuse a law enforcement officer's reasonable request under the circumstances for an evidentiary test where the officer had reasonable grounds to believe the person was in violation of subsection (a) of this section.(c) A person shall not operate, attempt to operate, or be in actual physical control of any vehicle on a highway and be involved in a crash or collision resulting in serious bodily injury or death to another and refuse a law enforcement officer's reasonable request under the circumstances for an evidentiary test where the officer has reasonable grounds to believe the person has any amount of alcohol or drugs in his or her system.(d)(1) A person who is convicted of a second or subsequent violation of subsection (a), (b), or (c) of this section when the person's alcohol concentration is proven to be 0.16 or more shall not, for three years from the date of the conviction for which the person's alcohol concentration is 0.16 or more, operate, attempt to operate, or be in actual physical control of any vehicle on a highway when the person's alcohol concentration is 0.02 or more. The prohibition imposed by this subsection shall be in addition to any other penalties imposed by law.(2) A person shall not operate, attempt to operate, or be in actual physical control of any vehicle on a highway when the person's alcohol concentration is 0.02 or more if the person has previously been convicted of a second or subsequent violation of subsection (a), (b), or (c) of this section within the preceding three years and the person's alcohol concentration for the second or subsequent violation was proven to be 0.16 or greater. A violation of this subsection shall be considered a third or subsequent violation of this section and shall be subject to the penalties of subsection 1210(d) of this title.(e) The fact that a person charged with a violation of this section is or has been entitled to use a drug under the laws of this State shall not constitute a defense against any charge of violating this section.(f) A person may not be convicted of more than one violation of subsection (a) of this section arising out of the same incident.(g) For purposes of this section and section 1205 of this title, the defendant may assert as an affirmative defense that the person was not operating, attempting to operate, or in actual physical control of the vehicle because the person:(1) had no intention of placing the vehicle in motion; and(2) had not placed the vehicle in motion while under the influence.(h) As used in subdivision (a)(3) of this section, "under the influence of a drug" means that a person's ability to operate a motor vehicle safely is diminished or impaired in the slightest degree. This subsection shall not be construed to affect the meaning of the term "under the influence of alcohol."(i) Evidence of the results of a standardized field sobriety test conducted by a law enforcement officer trained in Advanced Roadside Impaired Driving Enforcement or a certified Drug Recognition Expert's systematic evaluation of observable signs and symptoms of a person charged with a violation of this section shall be presumptively admissible at trial to demonstrate whether or not the person was operating under the influence in violation of this section.Amended by 2021 , No. 76, § 23, eff. 7/1/2021.Added 1969, No. 267 (Adj. Sess.), § 1; amended 1973, No. 16, § 1, eff. 3/1/1973; 1973, No. 79, § 1, eff. 5/23/1973; 1975, No. 10, § 2, eff. 4/9/1975; 1981, No. 103, §§ 2, 2a; 1983, No. 212 (Adj. Sess.), § 5; 1989, No. 68, § 2, eff. 12/1/1989; 1991, No. 55, § 2; 1997, No. 56 , § 1, eff. 8/1/1997; 1999, No. 116 (Adj. Sess.) , § 2; 1999, No. 160 (Adj. Sess.), § 15; 2001, No. 146 (Adj. Sess.) , § 1; 2005, No. 37 , § 1; 2007, No. 195 (Adj. Sess.) , § 4; 2011 , No. 56 , § 3; 2013, No. 169 (Adj. Sess.) , § 1, eff. 6/3/2014; 2017 , No. 83, § 161 (4); 2019 , No. 59, § 27; 2019, No. 164 (Adj. Sess.), § 22, eff. 1/1/2022.