Drug Impaired Driving

Every state has laws dealing with alcohol-impaired driving and drug-impaired driving. But unlike the laws for alcohol-impaired driving, those that address drug-impaired 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.
    • 6 states have per se laws in effect for one or more drugs.

Marijuana Drug-Impaired Driving Laws

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

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

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

In Two Years, Drugged Driving Deaths Rose While Drunk Driving Deaths Fell

Though fewer fatally injured drivers are testing positive for alcohol, more are being found with drugs in their system. Dr. Jim Hedlund, author of GHSA's latest report on drug-impaired driving, speaks with Forbes on the report's findings.

In Two Years, Drugged Driving Deaths Rose While Drunk Driving Deaths Fell

April 26, 2017
Article by Cheryl and Christopher Jensen

Responsibility.org Drugged Driving Grant Results: Florida

Florida State Safety Office

The Florida Department of Transportation State Safety Office was a recipient of GHSA and Responsibility.org’s 2016 grant program aimed at training law enforcement in drug recognition. Prior to receiving this grant, the Florida Highway Patrol had 11 certified Drug Recognition Experts (DREs), out of 1,869 total troopers. Faced with a high likelihood of marijuana legalization in the state and the subsequent potential for an increase in drug-impaired driving, FHP was able to train 27 additional DREs in 2016.

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