Drug Impaired Driving

Every state has laws dealing with alcohol-impaired driving and drug-impaired driving. But unlike the laws for drunk driving, those that address drugged driving are nuanced, difficult to enforce and prosecute and vary substantially by state.

In addition to general impairment laws, there are two basic laws that states tend to use when addressing drug-impaired driving:

  • Zero Tolerance laws make it illegal to drive with any measurable amount of specified drugs in the body. These laws are best suited for illegal drugs: if it is illegal to possess or use a drug, then it is reasonable to prohibit driving after the drug has been possessed and used.
    • 16 states have zero tolerance laws in effect for one or more drugs.
  • Per Se laws make it illegal to drive with amounts of specified drugs in the body that exceed set limits.
    • 5 states have per se laws in effect for one or more drugs.

Marijuana Drug-Impaired Driving Laws

17 states have zero tolerance or non-zero per se laws for marijuana.

  • 10 states have zero tolerance for THC or a metabolite.
  • 3 states have zero tolerance for THC but no restriction on metabolites.
  • 4 states have specific per se limits for THC
  • 1 state (Colorado) has a permissible inference law for THC

A PDF list of state marijuana-related laws is also available here.

NOTE: GHSA does not compile any additional data on drug impaired driving laws other than what is presented here. For more information, consult the appropriate State Highway Safety Office.

Sources: State Highway Safety Offices.

Short Term Description
Unlike the laws for drunk driving, those that address drugged driving are nuanced, difficult to enforce and prosecute and vary substantially by state.
Washington
DUID Zero Tolerance or Per se Laws for Some Drugs

Per se >0 for some drugs

Washington
Marijuana Possession and Use

Decriminalized and legal for recreational and medical use

Washington
Marijuana Impaired Driving

THC per se (5 ng)

Ohio
Marijuana Impaired Driving

THC per se (2 ng)

Ohio
DUID Zero Tolerance or Per se Laws for Some Drugs

Per se >0 for some drugs

Ohio
Marijuana Possession and Use

Decriminalized and legal for medical use

Montana
DUID Zero Tolerance or Per se Laws for Some Drugs

Per se >0 for some drugs

Montana
Marijuana Possession and Use

Legal for medical use

Montana
Marijuana Impaired Driving

THC per se (5 ng)

Colorado
DUID Zero Tolerance or Per se Laws for Some Drugs

Permissible inference law >0 for THC

Colorado
Marijuana Possession and Use

Decriminalized and legal for recreational and medical use

Colorado
Marijuana Impaired Driving

Permissible inference for THC (5 ng)

Vermont
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Vermont
Marijuana Possession and Use

Decriminalized and legal for recreational and medical use

Vermont
Marijuana Impaired Driving

None

Oregon
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Oregon
Marijuana Possession and Use

Decriminalized and legal for recreational and medical use

Oregon
Marijuana Impaired Driving

None

New Mexico
Marijuana Possession and Use

Decriminalized and legal for medical use

New Mexico
Marijuana Impaired Driving

None

New Mexico
DUID Zero Tolerance or Per se Laws for Some Drugs

None

New Jersey
DUID Zero Tolerance or Per se Laws for Some Drugs

None

New Jersey
Marijuana Possession and Use

Legal for medical use

New Jersey
Marijuana Impaired Driving

None

New Hampshire
DUID Zero Tolerance or Per se Laws for Some Drugs

None

New Hampshire
Marijuana Possession and Use

Decriminalized and legal for medical use

New Hampshire
Marijuana Impaired Driving

None

Nebraska
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Nebraska
Marijuana Possession and Use

Decriminalized

Nebraska
Marijuana Impaired Driving

None

Missouri
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Missouri
Marijuana Possession and Use

None

Missouri
Marijuana Impaired Driving

Decriminalized and legal for medical use

Mississippi
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Mississippi
Marijuana Possession and Use

None

Mississippi
Marijuana Impaired Driving

Decriminalized

Massachusetts
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Massachusetts
Marijuana Possession and Use

Decriminalized and legal for medical and recreational use

Massachusetts
Marijuana Impaired Driving

None

Maine
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Maine
Marijuana Possession and Use

Decriminalized and legal for medical and recreational use

Maine
Marijuana Impaired Driving

None

Hawaii
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Hawaii
Marijuana Possession and Use

Decriminalized and legal for medical use

Hawaii
Marijuana Impaired Driving

None

Connecticut
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Connecticut
Marijuana Possession and Use

Decriminalized and legal for medical use

Connecticut
Marijuana Impaired Driving

None

California
DUID Zero Tolerance or Per se Laws for Some Drugs

None

California
Marijuana Possession and Use

Decriminalized and legal for medical and recreational use

California
Marijuana Impaired Driving

None

Wisconsin
Marijuana Impaired Driving

Zero tolerance for delta-9-THC

Wisconsin
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Wisconsin
Marijuana Possession and Use

Illegal

Utah
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Utah
Marijuana Possession and Use

Legal for medical use

Utah
Marijuana Impaired Driving

Zero tolerance for THC and metabolites

South Dakota
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

South Dakota
Marijuana Possession and Use

Illegal

South Dakota
Marijuana Impaired Driving

Zero tolerance for THC and metabolites

Rhode Island
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Rhode Island
Marijuana Possession and Use

Decriminalized and legal for medical use

Rhode Island
Marijuana Impaired Driving

Zero tolerance for THC and metabolites

Pennsylvania
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Pennsylvania
Marijuana Possession and Use

Legal for medical use

Pennsylvania
Marijuana Impaired Driving

Zero tolerance for THC and metabolites

Oklahoma
Marijuana Possession and Use

Legal for medical use

Oklahoma
Marijuana Impaired Driving

Zero tolerance for THC and metabolites

Oklahoma
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

North Carolina
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

North Carolina
Marijuana Possession and Use

Decriminalized

North Carolina
Marijuana Impaired Driving

None

Minnesota
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Minnesota
Marijuana Possession and Use

Decriminalized and legal for medical use

Minnesota
Marijuana Impaired Driving

None

Michigan
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Michigan
Marijuana Possession and Use

Legal for medical and recreational use

Michigan
Marijuana Impaired Driving

Zero tolerance for THC

Kentucky
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Kentucky
Marijuana Possession and Use

Illegal

Kentucky
Marijuana Impaired Driving

None

Iowa
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Iowa
Marijuana Possession and Use

Illegal

Iowa
Marijuana Impaired Driving

Zero tolerance for THC

Indiana
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Indiana
Marijuana Possession and Use

Illegal

Indiana
Marijuana Impaired Driving

Zero tolerance for THC and metabolites

Illinois
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Illinois
Marijuana Possession and Use

Decriminalized and legal for recreational and medical use

Illinois
Marijuana Impaired Driving

THC per se (5 ng)

Georgia
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Georgia
Marijuana Possession and Use

Illegal

Georgia
Marijuana Impaired Driving

Zero tolerance for THC and metabolites

Delaware
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Delaware
Marijuana Possession and Use

Decriminalized and legal for medical use

Delaware
Marijuana Impaired Driving

Zero tolerance for THC and metabolites

Arizona
DUID Zero Tolerance or Per se Laws for Some Drugs

Zero tolerance for some drugs

Arizona
Marijuana Possession and Use

Legal for medical use

Arizona
Marijuana Impaired Driving

Zero tolerance for THC and metabolites

Wyoming
Marijuana Impaired Driving

None

Wyoming
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Wyoming
Marijuana Possession and Use

Illegal

Tennessee
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Tennessee
Marijuana Possession and Use

Illegal

Tennessee
Marijuana Impaired Driving

None

South Carolina
DUID Zero Tolerance or Per se Laws for Some Drugs

None

South Carolina
Marijuana Possession and Use

Illegal

South Carolina
Marijuana Impaired Driving

None

North Dakota
DUID Zero Tolerance or Per se Laws for Some Drugs

None

North Dakota
Marijuana Possession and Use

Decriminalized for legal for medical use

North Dakota
Marijuana Impaired Driving

None

Louisiana
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Louisiana
Marijuana Possession and Use

Illegal

Louisiana
Marijuana Impaired Driving

None

Kansas
Marijuana Possession and Use

Illegal

Kansas
Marijuana Impaired Driving

None

Kansas
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Idaho
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Idaho
Marijuana Possession and Use

Illegal

Idaho
Marijuana Impaired Driving

None

Florida
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Florida
Marijuana Possession and Use

Legal for medical use

Florida
Marijuana Impaired Driving

None

Arkansas
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Arkansas
Marijuana Possession and Use

Legal for medical use

Arkansas
Marijuana Impaired Driving

None

Alabama
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Alabama
Marijuana Possession and Use

Illegal

Alabama
Marijuana Impaired Driving

None

District of Columbia
Marijuana Impaired Driving

None

West Virginia
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Maryland
DUID Zero Tolerance or Per se Laws for Some Drugs

None

West Virginia
Marijuana Possession and Use

Legal for medical use

Maryland
Marijuana Possession and Use

Decriminalized and legal for medical use

West Virginia
Marijuana Impaired Driving

None

Maryland
Marijuana Impaired Driving

None

Nevada
DUID Zero Tolerance or Per se Laws for Some Drugs

Per se >0 for some drugs

Nevada
Marijuana Possession and Use

Decriminalized and legal for medical and recreational use

Nevada
Marijuana Impaired Driving

THC per se (2 ng)

New York
DUID Zero Tolerance or Per se Laws for Some Drugs

None

New York
Marijuana Possession and Use

Decriminalized and legal for medical use

New York
Marijuana Impaired Driving

None

Texas
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Alaska
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Texas
Marijuana Possession and Use

Illegal

Alaska
Marijuana Possession and Use

Decriminalized and legal for recreational and medical use

Texas
Marijuana Impaired Driving

None

Alaska
Marijuana Impaired Driving

None

Virginia
DUID Zero Tolerance or Per se Laws for Some Drugs

Per se >0 for some drugs

District of Columbia
DUID Zero Tolerance or Per se Laws for Some Drugs

None

Virginia
Marijuana Possession and Use

Decriminalized and legal for recreational and medical use

District of Columbia
Marijuana Possession and Use

Decriminalized and legal for recreational and medical use

Virginia
Marijuana Impaired Driving

None

States Focus on Impaired Driving Leading into Labor Day Weekend to Prevent Traffic Deaths

As summer winds down and millions of Americans take to the roads for the Labor Day weekend, GHSA is reminding motorists that State Highway Safety Offices and their federal and law enforcement partners are stepping up efforts to reduce drunk and drug-impaired driving, a preventable behavior that puts all road users at risk.

States Focus on Impaired Driving Leading into Labor Day Weekend to Prevent Traffic Deaths

As summer winds down and millions of Americans take to the roads for the Labor Day weekend, the Governors Highway Safety Association (GHSA) is reminding motorists that State Highway Safety Offices (SHSOs) and their federal and law enforcement partners are stepping up efforts to reduce drunk and drug-impaired driving, a preventable behavior that puts all road users at risk.

Maryland Awarded Grant for Second Year to Combat Drug-Impaired Driving

The Governors Highway Safety Association and the Foundation for Advancing Alcohol Responsibility, also known as Responsbility.org, have again awarded Maryland Department of Transportation Motor Vehicle Administration’s Highway Safety Office with a grant to support the state’s focus to prevent motor vehicle crashes from drug-impaired driving.

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