Drugged Driving – or Drug DWI – is a form of “Impaired Driving,” under N.C.G.S. 20-138.1. This is the same law that the State uses to convict drunk drivers. In other words, the same law governs drunk driving and drugged driving. But, operating under the influence of drugs, and operating under the influence of alcohol, are two very different things.

Remember, it’s not illegal to have a drink and drive; it is illegal to be drunk and drive. North Carolina’s current laws leave little to no room for the recreational marijuana user who, after after hitting his vape pen, gets behind the wheel.

Driving under the influence of drugs, even doctor prescribed medication, is one of those areas where the law just hasn’t kept up with the reality. Police officers and departments do a great job of catching drunk drivers: they have been trained on what signs to look for, and how to determine whether a driver is too drunk to be behind the wheel.

Police are not however, always adequately trained or given the proper resources to determine whether someone is driving high. Drugged Driving is difficult to prove, especially if the police do not get a chemical test. Moreover, a special type of police officer, known as a Drug Recognition Expert (DRE) is generally needed to assess and render a professional opinion as to whether a driver is impaired by drugs.


As usual, let’s start by reading the statute, N.C.G.S. 20-138.1. The burden is on the State to prove each of the following elements beyond a reasonable doubt:

A. That the Defendant drove; (and)

B. A vehicle; (and)

C. Upon a street, highway, or public vehicular area; (and)

· While under the influence of an impairing substance; or

· After having consumed sufficient alcohol that he has, at any relevant time after the driving, an alcohol concentration of 0.08 or more. The results of a chemical analysis shall be deemed sufficient evidence to prove a person’s alcohol concentration; or

· With any amount of a Schedule I controlled substance, as listed in G.S. 90-89, or its metabolites in his blood or urine.

The State must prove elements A, and B, and C all beyond a reasonable doubt, and must also prove ONE of the bullet points. In the business, we call these bullet points “Prongs.”


A lot of clients believe that if they don’t blow, the State won’t have a case. That is totally and completely wrong. I know what you want to ask me: “Derek, if I get stopped, do I blow or not?” Short answer: it’s complicated. But, I absolutely promise that throughout these posts, I will teach you everything I know about handling a DWI traffic stop. And, “everything that I know” may just come in helpful for you one day.

A chemical analysis is a test of a person’s breath, blood or other bodily fluid…to determine the person’s alcohol concentration or presence of an impairing substance. N.C.G.S. 20-4.01(3a). Generally, a person has the right to refuse chemical testing, but if you do so in North Carolina, your driver license will be revoked immediately for one year.

Without a chemical test, the State will prosecute a Drugged Driving case under the “Substantial Impairment” theory (AKA: Prong 1), which states: “while under the influence of an impairing substance“. To find the defendant guilty, the State does not need to provide the results of a chemical test, field sobriety tests, or other “reliable” impairment evidence. Prong 1 is intentionally vague. Without the results of a chemical test, proving impairment beyond a reasonable doubt can be difficult for the State.

Under Prong 1 Drugged Driving prosecutions, the State will submit other evidence of impairment, such as: the driver caused an accident, was speeding, driving too slowly, swerving, admitted to drug use, hostile/violent behavior, pinpoint pupils; I could go on and on ad infinitum.

A very hot topic in Drugged Driving litigation right now is whether the results of Standardized Field Sobriety Tests (SFST’s) should be admissible in court to show that defendant was operating under the influence of drugs. I believe that NHTSA developed SFST’s to detect alcohol impairment, not drug impairment, and that SFST’s are irrelevant in Drugged Driving cases. Moreover, the Massachusetts Supreme Court agrees with me, see Commonwealth v. Gerhardt, 477 Mass. 775 (2017).


If the State does possess the results of a chemical analysis, and the test shows positive for a Schedule 1 drug, defendant will be prosecuted under Prong 3. Here, defendant is guilty of Impaired Driving if he operates a vehicle, on a street, highway, or PVA, “with any amount of a Schedule I controlled substance, as listed in G.S. 90-89, or its metabolites in his blood or urine.” N.C.G.S. 20-138.1(a)(3).

What drugs are classified as Schedule 1? For a fully itemized link, click here. If you’d rather not comb through a medical textbook disguised in legalese, let me break it down for you: almost all opiates, fentanyl, codeine, heroin, morphine, MDMA, mescaline, peyote, psilocybin, and any type of synthetic cannabinoid.

The easiest way for the State to prove impairment is by introducing the results of a chemical test at trial. This is especially true in drunk driving, breath-test cases. These test results are admissible in court without the legal foundation necessary concerning introduction of other types of scientific evidence. N.C.G.S. 20-139.1(a) provides that, in an implied consent case, “a person’s alcohol concentration or the presence of any other impairing substance in the person’s body as shown by a chemical analysis is admissible in evidence,” as long as the test was carried out in accordance with the other provisions of N.C.G.S. 20-139.1.


Short answer, yes.

Between 2013 and 2014, the National Highway Traffic Safety Administration (NHTSA) conducted the National Roadside Survey of Alcohol and Drug Use by Drivers. The test was entirely voluntary, and anonymous. NHTSA had conducted similar tests in the early 1970’s and early 1990’s. Those results were recorded, studied, and compared. The 2013-2014 National Roadside Study of Alcohol and Drug Use by Drivers Study found a significant decreasing trend in alcohol use from the first study in 1973. During weekend, nighttime driving, when the most drunk drivers are on the road, only 8.3% of drivers tested alcohol positive, with only 1.5% having a blood alcohol content (BAC) greater than .08.

The same study (Drug Results) also tested drug presence through voluntary blood tests. While the mere presence of drugs in a driver’s bloodstream does not necessarily indicate impairment, the results are nonetheless surprisingly high.

In the 2013-2014 study, NHTSA found that 22.5% of weekend, nighttime drivers tested positive for drugs in their bloodstream. More than 1 out of every 5 drivers on the road tested positive for drugs! And remember, those were just the people that consented to a voluntary government blood draw! The morning commute isn’t much better: during weekdays, between 9:00 am and 5:00 pm, 19% of all drivers tested positive for drugs.

Results of the NHTSA studies tend to show that although drunk driving is trending down, drugged driving is rising fast!


To be found guilty of Driving While Impaired in North Carolina, the State must prove three things beyond a reasonable doubt:

That defendant was driving, a vehicle, upon a street, highway, or public vehicular area (PVA), plus either Prong 1 (Substantial Impairment), Prong 2 (BAC >.08), or Prong 3 (Schedule 1 Drug). If the State has the results of a chemical test, they will proceed under Prong 2 in Drunk Driving cases, and Prong 3 in Drugged Driving cases. Without a chemical test (or if defense counsel can suppress the chemical test), the State must proceed under Prong 1, the hardest for the State to prove.

In our next post, we will begin breaking down the statute itself and defining its key terms.

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