CONTENTS
- 1. Drug-Impaired Driving | Definition
- - The Difference Between Drug-Impaired Driving and Drunk Driving
- 2. Drug-Impaired Driving | Scope of Drugs
- - Narcotics, Psychotropic Drugs, and Cannabis
- - Hallucinogenic Substances
- 3. Drug-Impaired Driving | Strengthened Punishment Standards
- - Penalty Level for Drug Driving
- 4. Drug Driving | New Offense of Refusing a Drug Test
- - Request for a Drug Test
- - Penalty for Refusing a Drug Test
- 5. Drug Driving | Administrative Disposition of the Driver's License
- - Revocation of the Driver's License for Drug Driving
- - Revocation of the License for Refusing a Drug Test
- - Disqualification Period After License Revocation
- 6. Drug Driving | Response Tips
- - If You Need Assistance
1. Drug-Impaired Driving | Definition
Under the Road Traffic Act, drug-impaired driving refers to operating a vehicle while it is difficult to drive normally due to the influence of a drug.
Unlike drunk driving, even when there is no blood alcohol concentration standard, a state in which cognitive and judgment abilities are impaired by a drug may constitute drug-impaired driving.
Recently, as cases of driving after taking not only narcotics but also medical drugs and hallucinogenic substances have increased, drug-impaired driving is recognized as conduct that seriously threatens traffic safety.
The Difference Between Drug-Impaired Driving and Drunk Driving
Drug-impaired driving and drunk driving share the common feature that both prohibit driving in a state where the driver's normal driving ability is impaired.
The two acts, however, differ in their standards of assessment and methods of proof.
Drunk driving is assessed for a violation through the clear numerical standard of blood alcohol concentration.
When a certain level is exceeded, punishment for drunk driving follows regardless of the actual driving condition.
By contrast, drug-impaired driving has no specific numerical standard, and it is assessed mainly on whether the drug actually affected the driver's cognitive and judgment abilities.
In other words, the mere fact of taking a drug does not by itself constitute drug-impaired driving, and the driving condition at the time and the degree of the drug's influence are reviewed comprehensively.
2. Drug-Impaired Driving | Scope of Drugs
The “drug” defined under the Road Traffic Act is not limited to illegal narcotics.
The standard for assessing drug-impaired driving under the statute lies not in whether the substance is illegal, but in whether the substance affects the driver's cognition, judgment, and physical reactions so that normal driving is no longer possible.
Accordingly, even a legally prescribed drug or a chemical substance encountered in everyday life may constitute drug-impaired driving when a vehicle is operated in a state where normal driving is difficult due to its influence.
In light of this risk, the Road Traffic Act defines the scope of drugs broadly by applying separate statutes mutatis mutandis.
The “drug” defined under the Road Traffic Act means a substance falling under any of the following.
Narcotics, Psychotropic Drugs, and Cannabis
This refers to narcotics, psychotropic drugs, and cannabis under Article 2 of the Narcotics Control Act.
This includes not only illegal narcotics but also psychotropic drugs prescribed for medical purposes, such as propofol and zolpidem, and when driving ability is affected after taking them, drug-impaired driving may become an issue.
Hallucinogenic Substances
Under Article 22 of the Chemicals Control Act, this refers to chemical substances that cause excitement, hallucination, or anesthetic effects and are designated by Presidential Decree.
Specifically, the following substances constitute hallucinogenic substances.
ーOrganic solvents containing the above substances, such as thinner, adhesives, balloon-type products, and paints
ーButane gas
ーNitrous oxide (excluding use for medical purposes)
When a person drives after ingesting or inhaling such a hallucinogenic substance, this may constitute drug-impaired driving if the person is assessed to be in a state where normal driving is difficult, regardless of whether the substance produced a temporary state of excitement or anesthesia.
In particular, even a substance readily encountered in everyday life may become subject to punishment as drug-impaired driving if it affected driving ability, regardless of the purpose of use.
3. Drug-Impaired Driving | Strengthened Punishment Standards
As cases of driving after taking not only narcotics but also psychotropic drugs and hallucinogenic substances have increased recently, the Road Traffic Act has significantly strengthened the standards for punishing drug-impaired driving.
Because drug-impaired driving goes beyond a simple violation and carries a high risk of leading to a serious traffic accident, sanctions as severe as those for drunk driving apply.
Penalty Level for Drug Driving
Under Articles 45 and 148-2 of the Road Traffic Act, when a person drives a vehicle in a state where normal driving may be impaired due to the influence of drugs, the following criminal penalties apply.
▶ Road Traffic Act Article 148-2 (Penalty Provisions)
This raised the previous penalty standard of imprisonment for up to 3 years or a fine of up to 10 million won, reflecting the intent to punish drug driving strictly as a serious offense at a level similar to drunk driving.
In addition, if a person commits another offense within 10 years from the date on which a sentence of a fine or heavier became final after being convicted of drug driving, the person will receive an even heavier penalty.
▶Penalty Level for Reoffending Within 10 Years
Imprisonment for 2 to 6 years or a fine of 10 million to 30 million won
This penalty standard takes effect in April 2026, and the strengthened penalty provisions apply to drug driving conduct occurring on or after that date.
4. Drug Driving | New Offense of Refusing a Drug Test
To enhance the effectiveness of enforcement against drug driving, the Road Traffic Act newly introduced the offense of refusing a drug test.
This measure addresses the previous limitation that it was difficult to confirm drug use, and it closes the gaps in the enforcement process.
Request for a Drug Test
Under Article 45 of the Road Traffic Act, a police officer may test for drug use by methods prescribed by law, such as a saliva rapid-reagent test.
In this case, the driver must comply with the police officer's request for testing, and where the driver disputes the test result, the law provides that another test may be conducted by additional methods, such as drawing blood, with the driver's consent.
Penalty for Refusing a Drug Test
Where there are substantial grounds to suspect that normal driving is difficult due to the influence of drugs, refusing a drug test without justifiable reason may constitute the offense of refusing a drug test.
The criminal penalty that applies where the offense of refusing a drug test is established is as follows.
▶ Road Traffic Act Article 148-2 (Penalty Provisions)
Imprisonment for up to 5 years or a fine of up to 20 million won
If a person refuses a drug test and then commits the same offense again within 10 years from the date on which a sentence of a fine or heavier became final after conviction, the person will receive an even heavier penalty.
▶Penalty Level for Reoffending Within 10 Years
Imprisonment for 1 to 6 years or a fine of 5 million to 30 million won
This provision punishes the act of failing to comply with a test request itself, regardless of whether drugs were actually used, and it takes effect in April 2026.
5. Drug Driving | Administrative Disposition of the Driver's License
Apart from criminal punishment, drug driving also carries strong administrative dispositions, such as revocation or suspension of the driver's license.
In particular, not only drug driving but also the act of refusing a drug test is now clearly defined as grounds for license revocation, so the level of administrative disposition is further strengthened.
Revocation of the Driver's License for Drug Driving
Under Article 93 of the Road Traffic Act, where a person violates Article 45 (1) and drives a motor vehicle in a state where normal driving may be impaired due to the influence of drugs, the driver's license is revoked.
This is not a matter of mere discretionary disposition but constitutes grounds for license revocation prescribed by law.
Therefore, where drug driving is established, all driver's licenses may be revoked regardless of whether a fine or a suspended sentence is imposed.
Revocation of the License for Refusing a Drug Test
Even where a person does not comply with a police officer's request for a drug test despite substantial grounds to find that normal driving is difficult due to the influence of drugs, the driver's license is revoked.
In other words, even if actual drug use is not clearly confirmed, the act of refusing the test request alone may result in a license revocation disposition.
Disqualification Period After License Revocation
Drug driving does not stop at license revocation; it is also defined as a disqualifying ground that restricts reacquisition of a driver's license for a certain period.
In the following cases, a driver's license cannot be obtained for 2 years from the date the license was revoked.
▶ Violating, 2 or more times, the requirement to comply with a police officer's request for a drug test
▶ Causing a traffic accident while driving a vehicle in a state where normal driving is difficult due to the influence of drugs
In these cases, the license is not merely revoked; the acquisition of a new driver's license itself is restricted during the disqualification period.
6. Drug Driving | Response Tips
Drug driving cases are difficult to resolve on the bare facts alone, and the scope of criminal punishment and administrative disposition may vary greatly depending on how the case is handled during the investigation.
In particular, unlike drunk driving, drug driving has no clear numerical standard, so the initial response often serves as a key factor that determines the direction of the case.
▶ Do Not Conclude Based on Drug Use Alone
Whether the drug in question actually affected the driver's cognitive and judgment abilities so that normal driving was difficult is the key criterion for the determination.
Therefore, making unfavorable statements during the investigation stage on the premise of mere drug use alone calls for caution.
▶ Secure Objective Materials in the Case of Prescription Medication
In particular, materials that can establish whether the drug induces drowsiness, individual differences in reaction, and the driving condition at the time of the accident or enforcement may serve as key evidence in disputing whether drug driving is established.
▶ Review the Lawfulness of the Drug Testing Procedure
Whether the police officer could request a drug test, whether the testing method was lawful, and whether there were errors in interpreting the test results often become points at issue in the case.
If You Need Assistance
Drug-impaired driving can lead not only to criminal punishment but also to administrative measures such as revocation of the driver's license at the same time.
Disadvantages may therefore arise unless a response strategy that considers both criminal liability and the administrative license measure together is established from the investigation stage.
It is important to organize the facts and analyze the legal issues sufficiently at the early response stage, and then set the direction of the response with professional assistance.
Depending on the case, our firm comprehensively analyzes the drug components and their effects, the circumstances of ingestion, the legality of the testing procedure, and objective records regarding the driving condition, and provides comprehensive assistance.
In addition, at the investigation stage we set the direction of the response so that unnecessary statements do not lead to unfavorable interpretations, and we then establish a practical defense strategy that takes into account both the level of criminal punishment and the scope of the administrative measure.
If you need legal assistance regarding drug-impaired driving, we encourage you to prepare a response strategy together with a traffic accident attorney at any time.
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