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 reasonable 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.

As Drivers Return to the Roadways, Seven States Receive Grants to Stop High Risk Impaired Driving

FOR IMMEDIATE RELEASE
July 1, 2020

CONTACT: Adrian Nicholas, 202-580-7934, anicholas@ghsa.org

GHSA & Responsibility.org to Award $245,000 in Highway Safety Grants

WASHINGTON, D.C. – For the sixth consecutive year, the Governors Highway Safety Association (GHSA) and the Foundation for Advancing Alcohol Responsibility (Responsibility.org) are awarding grants to help states keep Americans safe from the most dangerous impaired drivers.

Dangerous Driving Habits at Risk of Returning, Safety Group Warns

As driving begins to return to normal levels across the country after months of lockdown, motorists may fall back into bad driving habits. Even though drivers know that their risky behavior is wrong, many do it anyway, particularly those involved in a recent crash.

Dangerous Driving Habits at Risk of Returning, Safety Group Warns

Story by Tanya Mohn
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DUID Training Grant: Nevada

In 2019, through a grant from the Foundation for Advancing Alcohol Responsibility (Responsibility.org) and GHSA, the Nevada Office of Traffic Safety contracted with Understanding Legal Marijuana, LLC., a company focused on providing training and consultation to states and local governments considering or dealing with the recent passage of legal marijuana initiatives, to host a training class titled “Marijuana DUI Investigations with Green Lab.”

DUID Training Grant: Vermont

Through a grant from the Foundation for Advancing Alcohol Responsibility (Responsibility.org) and GHSA, the Vermont State Highway Safety Office – Behavioral Safety Unit (SHSO - BSU) provided Advanced Roadside Impaired Driving Enforcement (ARIDE) training to law enforcement.

Vermont is experiencing an increase in drug impaired driving. Impairment by alcohol, drugs or both was a contributing factor in nearly half of Vermont’s fatal crashes in 2018, yet only a small percentage of law enforcement officers in Vermont are currently ARIDE trained.

DUID Training Grant: South Dakota

The South Dakota Office of Highway Safety (SDOHS) received a grant from GHSA and the Foundation for Advancing Alcohol Responsibility (Responsibility.org) to hold an Impaired Driving Conference in December 2019. Nearly 100 law enforcement officers attended, as well as prosecutors from South Dakota, North Dakota, Iowa and Nebraska.

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