Stay up to date with

State Map

SELECT A STATE from the National Totals dropdown menu to view statistics about impaired driving and underage drinking.

SELECT A LAW to view the details of each state’s impaired driving and underage drinking laws.

See how your state measures up to the rest of the country!

State Law: DUID Affirmative Defense
  • Affirmative defense
  • No affirmative defense
  • Special circumstances

In every state in the country, it is illegal to drive while impaired by drugs. Some states have zero tolerance (ZT) or per se DUID laws that make it illegal for a person to drive with certain drugs (or more than a specified amount of certain drugs) in their system. The laws operate similarly to the nation’s 0.08 BAC laws for alcohol. However, they typically afford drugged drivers an absolute “affirmative defense” essentially exempting those who take medications pursuant to a valid prescription. The defense applies to the ZT and per se provisions only; it does not apply to the traditional DUI provisions. The rationale for this is simple. First, drivers should not be entitled to drive while impaired by any substance, regardless of its legality. Thus, just as a driver with a blood alcohol level below 0.08 is guilty of DUI if they drive impaired, a driver with a valid prescription for a drug is guilty of DUI if they drive while impaired. Second, doctors cannot authorize a person to drive while impaired by giving them a prescription.

The following chart contains links to the current affirmative defense statutes.

For more information about drug-impaired driving laws and enforcement, please refer to this resource. To learn more about the drug-impaired driving laws in your state, visit our DUID map and our marijuana-impaired driving map.

To submit a law update, please contact out Director of Traffic Safety at

2015 Alcohol-Impaired Driving Fatality DataNational
Total Alcohol-Impaired Driving Fatalities10,265
Percent of Alcohol-Impaired Driving Fatalities of Total Fatalities29.3
Under 21 Alcohol-Impaired Driving Fatalities1,021
Percent of Under 21 Alcohol-Impaired Driving Fatalities of Total Under 21 Fatalities23.0
2015 Alcohol-Impaired Driving Fatalities per 100,000 Population
Alcohol-Impaired Driving Fatalities per 100K population3.2
Under 21 Alcohol-Impaired Driving Fatalities per 100K population1.2
2006-2015 % Change in Alcohol-Impaired Driving Fatalities per 100K Pop
10-year Change in Alcohol-Impaired Driving Fatalities per 100K pop-29.0
10-year Change in Under 21 Alcohol-Impaired Driving Fatalities per 100K pop-49.7
Percent of Alcohol-Impaired Driving Fatalities Involving high BAC drivers (.15+)*
Percent of Drivers in Fatal Crashes Involving Repeat Offenders
BAC .08-.1427.0
BAC .15+73.0
2013 and 2014 12-20 Year Old Alcohol Consumption (latest available)
Past Month Alcohol Consumption22.8
Binge Drinking in Past 30-days14.0
2015 Arrest Data
Under 18: Driving under the influence5,064
Total: Driving under the influence833,833
Under 18: Liquor laws33,155
Total: Liquor laws204,665
Under 18: Drunkenness4,243
Total: Drunkenness314,856

Alcohol-Impaired Driving Fatality Data Source: NHTSA/FARS, 10/16

*Among drivers with a known alcohol test result

*Youth Consumption Data Source: SAMHSA, Office of Applied Studies, National Survey on Drug Use and Health, 12/15, (

*Arrest Data Source: 2015 FBI Uniform Crime Report (Tables 38 and 69)

**Drunkenness is not considered a crime in some states; therefore, the figures may vary widely from state to state

*Limited, incomplete, or no data were reported by the District of Columbia, Florida, Illinois, and New York in the 2015 Uniform Crime Report. Data should be used with caution and should not be compared to other states or previous year data.

Note: Because the number of agencies submitting arrest data varies from year to year, users are cautioned about making direct comparisons between 2015 arrest totals and those published in previous years’ editions of Crime in the United States. Further, arrest figures may vary widely from state to state because some Part II crimes of the Uniform Crime Report are not considered crimes in some states.

For a comprehensive report on the 2016 State of Drunk Driving Fatalities in America, click here.

StateState Law
AlabamaNo affirmative defense
AlaskaAffirmative defense
ArizonaSpecial circumstances
ArkansasNo affirmative defense
CaliforniaSpecial circumstances
ColoradoNo affirmative defense
ConnecticutNo affirmative defense
DelawareAffirmative defense
District of ColumbiaNo affirmative defense
FloridaNo affirmative defense
GeorgiaSpecial circumstances
HawaiiNo affirmative defense
IdahoNo affirmative defense
IllinoisNo affirmative defense
IndianaAffirmative defense
IowaAffirmative defense
KansasNo affirmative defense
KentuckyAffirmative defense
LouisianaAffirmative defense
MaineNo affirmative defense
MarylandAffirmative defense
MassachusettsNo affirmative defense
MichiganNo affirmative defense
MinnesotaAffirmative defense
MississippiNo affirmative defense
MissouriNo affirmative defense
MontanaNo affirmative defense
NebraskaNo affirmative defense
NevadaNo affirmative defense
New HampshireNo affirmative defense
New JerseyNo affirmative defense
New MexicoNo affirmative defense
New YorkNo affirmative defense
North CarolinaSpecial circumstances
North DakotaAffirmative defense
OhioAffirmative defense
OklahomaNo affirmative defense
OregonNo affirmative defense
PennsylvaniaAffirmative defense
Rhode IslandNo affirmative defense
South CarolinaNo affirmative defense
South DakotaNo affirmative defense
TennesseeNo affirmative defense
TexasNo affirmative defense
UtahAffirmative defense
VermontNo affirmative defense
VirginiaNo affirmative defense
WashingtonSpecial circumstances
West VirginiaNo affirmative defense
WisconsinAffirmative defense
WyomingNo affirmative defense