What You Need to Know about Substance Use and Driving – Including Marijuana

"Each December, we recognize National Impaired Driving Prevention Month to raise awareness about the dangers of impaired driving and how to prevent impaired driving and related crashes, injuries, and deaths.

Driving while impaired by any substance is dangerous and illegal. The following substances can impair driving:

• Alcohol
• Marijuana
• Other illicit drugs like heroin, cocaine, methamphetamine, or hallucinogens
• Some prescription medications like opioids and antidepressants
• Some over-the-counter medications like sleep aids and allergy medicines

Fast Facts

• 11,654 people in the United States were killed in alcohol-impaired driving crashes in 2020—a 14% increase from 2019. That’s about 32 people every day or one person every 45 minutes.^[i]
• 7 million Americans reported driving under the influence of marijuana or other illicit drugs in 2020.^[ii]
• Alcohol and marijuana were the two most commonly reported substances involved in impaired driving in 2018, with 8% and 4.7% of the U.S. population aged ≥16 years reporting alcohol and marijuana respectively.^[iii]
• 1 in 8 high school student drivers reported driving after using marijuana at least once during the past month in 2017.^[iv]

How Does Substance Use Affect Driving?

How Marijuana Use Affects Driving

Driving is a complex task that requires your full attention to stay safe and alert. Marijuana use affects areas of the brain that control your body’s movements, balance, coordination, memory, and judgment. Marijuana use can impair important skills required for safe driving by:

• Slowing your reaction time and ability to make decisions
• Making it difficult to multitask
• Impairing coordination
• Distorting perception^{[i],[ii],[iii]}

If you are impaired, you cannot drive safely. It is illegal and dangerous to drive if you are impaired after using marijuana.

How Alcohol Affects Driving

The amount of alcohol in a person’s system is called blood alcohol concentration (BAC). Most states have set the legal BAC limit for driving at 0.08 grams of alcohol per deciliter (g/dL); the limit is 0.05g/dL in Utah.^[i] However, impairment starts at lower BAC levels, with even small amounts of alcohol affecting the ability to drive. The effects of alcohol use on driving include:

• Difficulty steering
• Reduced ability to respond to emergency driving situations
• Reduced ability to maintain lane position and brake appropriately
• Reduced ability to process what is happening on the road.."
  Impaired driving 

FASD Awareness

"September is FASD Awareness Month. FASD Awareness Month is an expansion of FASD Awareness Day that has been held each year on September 9th since 1999.

Alcohol use during pregnancy can cause fetal alcohol spectrum disorders, which are physical, behavioral, and intellectual disabilities that last a lifetime. Often, a person with an FASD has a mix of these problems. It is recommended that women who are pregnant or might be pregnant not drink alcohol. Fetal alcohol spectrum disorders are completely preventable if a developing baby is not exposed to alcohol before birth....:

Fetal Alcohol Syndrome

Alcohol Poisoning Deaths

"On average, 6 people died every day from alcohol poisoning in the US from 2010 to 2012. Alcohol poisoning is caused by drinking large quantities of alcohol in a short period of time. Very high levels of alcohol in the body can shutdown critical areas of the brain that control breathing, heart rate, and body temperature, resulting in death. Alcohol poisoning deaths affect people of all ages but are most common among middle-aged adults and men..."
Alcohol poisoning

Alcohol Deaths

"Excessive alcohol use is a leading cause of preventable death. This dangerous behavior accounted for approximately 88,000 deaths per year from 2006–2010, and accounted for 1 in 10 deaths among working-age adults aged 20–64 years. Excessive alcohol use shortened the lives of those who died by about 30 years...
Alcohol Deaths

Alcohol Screening and Brief Intervention

"CDC recently reported that 1 in 8 women and 1 in 5 high school girls binge drink, increasing their risk of breast cancer, heart disease, sexually transmitted infections, and unintended pregnancy. CDC also reports that 1 in 13 women drink during pregnancy, increasing their risk of miscarriage, stillbirth, and a range of lifelong disorders in their babies known as fetal alcohol spectrum disorders (FASDs)..."
Alcohol Screening

Results from the 2011 National Survey on Drug Use and Health: Summary of National Findings

"This report presents a first look at results from the 2011 National Survey on Drug Use and Health (NSDUH), an annual survey of the civilian, noninstitutionalized population of the United States aged 12 years old or older. The report presents national estimates of rates of use, numbers of users, and other measures related to illicit drugs, alcohol, and tobacco products. The report focuses on trends between 2010 and 2011 and from 2002 to 2011, as well as differences across population subgroups in 2011. NSDUH estimates related to mental health, which were included in national findings reports prior to 2009, are not included in this 2011 report..."
http://www.samhsa.gov/data/NSDUH/2k11Results/NSDUHresults2011.pdf

Excessive Drinking Costs U.S. $223.5 Billion

"Excessive alcohol consumption is known to kill about 79,000 people in the United States each year, but a new study released by the CDC and The Lewin Group shows that it also has a huge impact on our wallets as well.

The cost of excessive alcohol consumption in the United States reached $223.5 billion in 2006 or about $1.90 per drink. Almost three-quarters of these costs were due to binge drinking. Binge drinking is defined as consuming four or more alcoholic beverages per occasion for women or five or more drinks per occasion for men, and is the most common form of excessive alcohol consumption in the United States..."

FTC Launches 2011 "We Don't Serve Teens" Education Campaign
"As the new school year starts, the Federal Trade Commission is launching its 2011 “We Don’t Serve Teens” consumer education campaign, which warns of the hazards of underage drinking. The FTC and a coalition of private and public groups are distributing education materials that support the legal drinking age of 21 and emphasize that what parents know about underage drinking can make a huge difference in their children’s future..."
Veiw We Don't Serve Teens program.

The Cool Spot: the Young Teens Place for Info on Alcohol
Find tips for talking to teens about alcohol, peer pressure, right to resist, and real life.

Policy Impact: Impaired Driving
"What's the Issue?
Each year, millions of people choose to drive while under the influence of alcohol, sometimes with devastating results. In 2009, almost 11,000 people were killed in crashes involving impaired drivers, nearly one-third of all traffic deaths.

Alcohol-impaired driving crashes claim the lives of the most vulnerable: in a single year, these crashes killed more than 180 children younger than 14.2 Half of the children killed in alcohol-impaired driving crashes were riding in the car with the impaired driver.

These deaths are preventable. Research has identified proven policies that can keep alcohol-impaired drivers off the road and save thousands of lives each year..."

Ignition Interlocks: A Proven Means for Preventing Impaired Driving Re-Arrests
"A man decides it's best to not have a drink in a restaurant with friends. He has to drive home, and since his arrest for driving while intoxicated (DWI) a few months ago, he's had a court-ordered ignition interlock installed in his car. This device prevents the car from starting if there's alcohol on his breath. A woman puts her children in their booster seats, blows into an ignition interlock, and starts her car's engine. Since her conviction for DWI, she hasn't been faced with the dilemma of how to get her kids to school and drive to work. The court mandated she have an ignition interlock installed rather than have her license suspended. She's thankful that she can drive legally, as long as her interlock detects she's not impaired by alcohol..."

Reducing Alcohol-Impaired Driving: Ignition Interlocks
"Ignition interlocks are devices that can be installed in motor vehicles to prevent operation of the vehicle by a driver who has a blood alcohol concentration (BAC) above a specified level (usually 0.02% – 0.04%). Interlocks are most often installed in vehicles of people who have been convicted of alcohol-impaired driving to give them an opportunity to drive legally.

Summary of Task Force Recommendations & Findings
The Task Force on Community Preventive Services recommends the use of ignition interlocks for people convicted of alcohol-impaired driving on the basis of strong evidence of their effectiveness in reducing re-arrest rates while the interlocks are installed. Public health benefits of the intervention are currently limited by the small proportion of offenders who install interlocks in their vehicles. More widespread and sustained use of interlocks among this population could have a substantial impact on alcohol-related crashes..."

Alcohol And Crime: Data From 2002 To 2008
"This webpage includes analyses from four data sources: the National Incident-Based Reporting System (NIBRS), the National Crime Victimization Survey (NCVS), the Survey of Inmates in State and Federal Correctional Facilities (SISFCF), and the Survey of Inmates in Local Jails (SILJ). Each data source examines the involvement of alcohol and violent crime from different perspectives and different sets of criminal behaviors. In NIBRS law enforcement officers are asked to record whether alcohol use by victims, offenders, or both was involved in the incident. In NCVS victims are asked to report whether they believe the offenders had consumed alcohol prior to or during the crime. Finally, in the inmate surveys prison and jail inmates are asked if they were using alcohol at the time of the crime for which they were incarcerated.

The NCVS captures the broadest range of crime and includes nonfatal crime reported and not reported to law enforcement. Because the NCVS measures the number of victimizations, it does not restrict identifying an incident as alcohol-involved based on the quantity of alcohol consumed by the offender or the degree of impairment resulting from the alcohol consumption. NIBRS captures fatal and nonfatal crimes reported to law enforcement, which are likely more serious than those captured by NCVS. Victimizations captured by NCVS and offenses known to police reflected in NIBRS may underestimate domestic violence; however, it is not clear which data source provides better information on the characteristics of these crimes..."

Underage Alcohol Use: Where Do Young People Drink?
"# A majority (53.4 percent) of current alcohol users aged 12 to 20 drank at someone else's home the last time they used alcohol, and another 30.3 percent drank in their own home
# The percentage of underage alcohol users who had their most recent drink in a car or other vehicle peaked at 10.1 percent at age 16 (12.8 percent of females and 7.3 percent of males)
# Among 20-year-old current drinkers, 20.0 percent of females drank in a restaurant, bar, or club the last time they used alcohol compared with 10.2 percent of males."