Drug-impaired driving is measured in several different ways: self-reported behavior, biological detection, estimates above legal limits, and evaluations by trained officers. These measures are not interchangeable, but together they show the scale and complexity of drug-impaired driving across populations and periods.
Key Drug-Impaired Driving Statistics
The following figures summarize the most useful measures across surveys, roadside studies, toxicology, and enforcement:
- In 2018, 12.0 million U.S. residents aged 16 and older reported past-year marijuana-impaired driving.
- In 2018, 4.7% of U.S. residents aged 16 and older reported past-year marijuana-impaired driving.
- In 2018, 2.3 million U.S. residents aged 16 and older reported driving under the influence of illicit drugs other than marijuana.
- In 2018, 8.0% of U.S. residents aged 16 and older reported alcohol-impaired driving.
- In 2018, male marijuana-impaired driving prevalence was 6.2% among U.S. males aged 16 and older.
- In 2018, marijuana-impaired driving prevalence was 12.4% among U.S. residents aged 21–25.
- In 2013–2014, 15.1% of U.S. weekend nighttime drivers tested positive for illicit drugs.
- In 2013–2014, 12.6% of U.S. weekend nighttime drivers tested positive for THC.
- In 2007, 45.3% of U.S. drivers with a blood alcohol concentration of at least 0.08 also used drugs.
- Among U.S. drivers who used alcohol and cannabis during 2016–2019, 42% reported driving under the influence.
- Among those U.S. alcohol-and-cannabis users, 14% reported combined alcohol/cannabis driving under the influence during 2016–2019.
- In an Arizona trauma-center study from 2008–2014, 10% of injured drivers aged 16–20 were positive for alcohol and THC.
- In a Catalonia roadside study, 16.4% of tested drivers were positive for a non-alcohol drug.
- In Norway during 2008–2009, 4.8% of 9,410 oral-fluid samples were positive for a psychoactive substance.
- In 2022, 8,350 active U.S. drug recognition experts conducted 23,278 evaluations.
- From 2009–2022, 155,875 U.S. officials received Advanced Roadside Impaired Driving Enforcement training.
Contents
- Drug-impaired driving statistics in U.S. self-reported surveys
- Drug-impaired driving data by age, sex, and race
- Roadside drug-impaired driving trends and toxicology
- Cannabis, polysubstance, and alcohol-drug driving statistics
- Drug-impaired driving statistics from injured and general drivers
- Drug-impaired driving enforcement, evaluation, and training
Drug-Impaired Driving Statistics in U.S. Self-Reported Surveys
The CDC’s analysis of weighted 2018 National Survey on Drug Use and Health estimates covers the U.S. civilian, noninstitutionalized population aged 16 and older. Because these are self-reports, they measure reported behavior rather than toxicologically confirmed impairment.
| Self-reported outcome | Period and population | Result |
|---|---|---|
| Marijuana-impaired driving | United States, age 16+, 2018 | 12.0 million; 4.7% |
| Other-illicit-drug driving | United States, age 16+, 2018 | 2.3 million; 0.9% |
| Alcohol-impaired driving | United States, age 16+, 2018 | 20.5 million; 8.0% |
| Alcohol-impaired driving | United States, age 16–25, 2014 | 12.4% |
| Marijuana-impaired driving | United States, age 16–25, 2014 | 3.2% |
The 20.5 million alcohol-impaired-driving estimate and the 8.0% estimate were CDC-cited unpublished NSDUH estimates. The other 2018 figures are also subject to self-report limitations. CDC, “Driving Under the Influence of Marijuana and Illicit Drugs Among Persons Aged ≥16 Years — United States, 2018”
These figures should not be added together: the categories can overlap, and they describe different substances and reporting questions. They also should not be treated as a direct estimate of crashes or demonstrated impairment.
Drug-Impaired Driving Data by Age, Sex, and Race
The 2018 survey shows substantial variation by demographic group. The estimates below are prevalence measures for the specified U.S. population, not rates of drug detection among drivers stopped or injured.
| Group | Marijuana-impaired driving | Other-illicit-drug driving |
|---|---|---|
| Males aged 16+ | 6.2% | 1.3% |
| Females aged 16+ | 3.2% | 0.5% |
| Ages 21–25 | 12.4% | 1.9% |
| Ages 16–20 | 9.2% | — |
| Ages 26–34 | — | 1.9% |
| Ages 65+ | 0.6% | — |
The highest listed marijuana-impaired-driving prevalence was 12.4% among people aged 21–25, while the estimate was 0.6% among those aged 65 and older. Among other-illicit-drug driving, the estimates were 1.9% for ages 21–25 and 26–34.
Race and ethnicity estimates also varied, although subgroup precision matters. Non-Hispanic multiracial respondents had a 9.2% marijuana-impaired-driving prevalence, identified as a small subgroup estimate, while non-Hispanic Asian respondents had 2.3%; non-Hispanic Black respondents had 0.6% other-illicit-drug driving prevalence. CDC, “Driving Under the Influence of Marijuana and Illicit Drugs Among Persons Aged ≥16 Years — United States, 2018”
Roadside Drug-Impaired Driving Trends and Toxicology
Roadside testing measures whether a substance or metabolite is detected in a specimen. A positive result does not by itself prove that a driver was impaired at the time of testing, and specimen type, analytes, thresholds, participation, and sampling design affect comparisons.
| Roadside measure | Period and population | Result |
|---|---|---|
| Illicit-drug positivity | United States weekend nighttime drivers, 2013–2014 | 15.1% |
| THC positivity | United States weekend nighttime drivers, 2013–2014 | 12.6% |
| Alcohol positivity | United States weekend nighttime drivers, 2013–2014 | 8.3% |
| Illegal-drug use | United States weekend-night drivers, 2007 | 10.5% |
| Medication positivity | United States weekend-night drivers, 2007 | 3.0% |
| Marijuana presence | United States weekend-night drivers, 2007 | 6.1% |
The 2007 National Roadside Survey collected oral fluid from 7,719 respondents and blood from 3,276 respondents. Among drivers with a blood alcohol concentration of at least 0.08, 45.3% also used drugs, a toxicology association within that subgroup rather than a causal estimate. NHTSA, “2007 National Roadside Survey of Alcohol and Drug Use by Drivers: Drug Results”
The 2013–2014 results likewise describe biological positivity, not necessarily legal impairment. THC presence is especially important to interpret cautiously because detection is not a direct measure of when or whether impairment occurred. CDC, “Driving Under the Influence of Marijuana and Illicit Drugs Among Persons Aged ≥16 Years — United States, 2018”
Cannabis, Polysubstance, and Alcohol-Drug Driving Statistics
A 2016–2019 U.S. NSDUH analysis examined drivers who used alcohol and cannabis during the period. Within that conditional subgroup, 42% reported driving under the influence, including alcohol-only, cannabis-only, and combined reports.
| Reported DUI category | U.S. alcohol-and-cannabis users, 2016–2019 |
|---|---|
| Any DUI | 42% |
| Alcohol-only DUI | 8% |
| Cannabis-only DUI | 20% |
| Combined alcohol/cannabis DUI | 14% |
The categories describe self-reported outcomes within the subgroup and should not be read as prevalence among all U.S. drivers. Simultaneous alcohol and cannabis use was associated with adjusted odds ratios of 2.88 for cannabis-only DUI and 3.51 for combined DUI; the adjusted odds ratio for alcohol-only DUI was 0.59.
These are observational associations, not proof that simultaneous use caused the outcomes. CDC Stacks, “Simultaneous Alcohol/Cannabis Use and Driving Under the Influence in the U.S.”
An exposure measure provides additional context but is not a driving measure: past-year marijuana use among U.S. adults aged 18–25 was 34.8% in 2018. In an Arizona trauma-center study covering 2008–2014, 10% of injured drivers aged 16–20 were positive for both alcohol and THC.
The trauma-center sample and biological measure limit direct comparison with national self-reports. CDC, “Driving Under the Influence of Marijuana and Illicit Drugs Among Persons Aged ≥16 Years — United States, 2018”
Drug-Impaired Driving Statistics from Injured and General Drivers
International roadside studies demonstrate why geography and testing design must remain explicit. The Catalonia study used tested drivers, while the Norwegian survey used oral-fluid samples from randomly selected drivers; neither positive detection result establishes impairment by itself.
| Study and population | Measure | Result |
|---|---|---|
| Catalonia tested drivers | Non-alcohol drug positivity | 16.4% |
| Catalonia tested drivers | Alcohol positivity | 1.3% |
| Catalonia tested drivers | THC detection | 12.4% |
| Catalonia tested drivers | Methamphetamine detection | 3.4% |
| Catalonia tested drivers | Multiple-drug positivity | 3.7% |
| Norway random drivers, 2008–2009 | Psychoactive-substance positivity, 9,410 oral-fluid samples | 4.8% |
| Norway random drivers, 2008–2009 | Medicinal-drug positivity | 3.2% |
| Norway random drivers, 2008–2009 | Illegal-drug positivity | 1.5% |
| Norway random drivers, 2008–2009 | THC positivity | 1.1% |
In Catalonia, male drivers had an odds ratio of 7.00 for any drug positivity, with a confidence interval of 4.45–11.03. Van or lorry drivers had an odds ratio of 2.34 for any drug positivity and 4.28 for methamphetamine positivity, while nighttime driving had an odds ratio of 2.75 for methamphetamine positivity; the van-or-lorry methamphetamine estimate had a confidence interval of 1.17–15.58. PLOS ONE, “Prevalence of drug use among drivers based on mandatory, random tests in a roadside survey”
Norway’s survey found zopiclone positivity of 1.4% and estimated driving above legislative limits at about 0.6% for illegal drugs. That legal-limit figure is a derived estimate rather than direct blood testing, so it is not directly comparable with the positivity results. PubMed, “Norwegian roadside survey of alcohol and drug use by drivers (2008-2009)”
Drug-Impaired Driving Enforcement, Evaluation, and Training
Enforcement statistics measure institutional capacity and activity rather than the prevalence of impairment in the driving population. NHTSA reported 8,350 active U.S. drug recognition experts and 1,605 instructors in 2022.
| Enforcement measure | United States result |
|---|---|
| Active DREs in 2022 | 8,350 |
| DRE instructors in 2022 | 1,605 |
| DRE evaluations in 2022 | 23,278 |
| Officials receiving ARIDE training, 2009–2022 | 155,875 |
| DRE initial classroom training | 72 hours |
| DRE initial field work | About 50 hours |
DRE evaluations are not equivalent to arrests or confirmed impairment. The initial DRE program includes 72 classroom hours and about 50 field-work hours, while the cumulative ARIDE total covers officials trained from 2009 through 2022. NHTSA, “Enforcement of Drug-Impaired Driving”
NHTSA-cited studies found above 85% DRE-to-toxicology agreement in some settings. Other studies found lower agreement, and agreement between an evaluation and toxicology result is not proof of causation or a universal performance rate. NHTSA, “Enforcement of Drug-Impaired Driving”