By Edmund Murphy

Last updated: 03 October 2023 & medically reviewed by Hailey Shafir

When someone sits behind the wheel of a car, they become responsible for their own safety and that of other road users. Driving requires awareness, reaction speed, and the ability to complete complex maneuvers, all of which become impaired when intoxicated. Driving a vehicle while under the influence of drugs or alcohol puts your life and the life of others at risk. In 2016, nearly 50% of fatal car accidents involved a driver who was under the influence of drugs and alcohol, and one person dies each hour because of drunk driving accidents.

Key takeaways:

  • In 2012, 29.1 million people admitted to driving under the influence of alcohol - that’s more than the population of Texas

  • The federal limit to legally drive in the United States is a blood alcohol content (BAC) of 0.08% or less, which will take the average adult 12 oz beer, 5 oz glass of wine, or a shot of liquor consumed within an hour to reach
  • According to the National Highway Traffic Safety Administration’s (NHTSA) National Roadside Survey, more than 16% of weekend and nighttime drivers tested positive for illegal, prescription, or over-the-counter medications (11% tested positive for illegal drugs)
Driving While Impaired (DWI) Alcohol and Drugs

Drug and drunk driving at a glance

  • An estimated 32% of fatal car crashes involve an intoxicated driver or pedestrian. (NHTSA)

  • 3,952 fatally injured drivers tested positive for drug involvement. (FARS)

  • Car crashes are the leading cause of death for teens, and about a quarter of those crashes involve an underage drinking driver. (SAMHSA)

  • On average, two in three people will be involved in a drunk driving crash in their lifetime. (NHTSA)

  • In 2012, 29.1 million people admitted to driving under the influence of alcohol - that’s more than the population of Texas

  • According to the 2013 National Survey on Drug Use and Health (NSDUH), an estimated 9.9 million people aged 12 or older (or 3.8 percent of adolescents and adults) reported driving under the influence of illicit drugs during the year prior to being surveyed

Drinking & driving

The federal limit to legally drive in the United States is a blood alcohol content (BAC) of 0.08% or less, which will take the average adult 12 oz beer, 5 oz glass of wine, or a shot of liquor consumed within an hour to reach. Further to this, some states have hard-line punishments in place for 1st time DWI offenders, with Arizona, Tennessee, and Georgia having mandatory jail time for 1st offenders, meaning a DWI conviction on their record and likely a license suspension. 

There is a good reason for these harsh penalties for drunk driving, as alcohol is known to: [1]

  • Be a central nervous system (CNS) depressant that affects the brain's response times and motor functions

  • Slowing information processing, cognitive skills, and ability to concentrate

  • Lower hand-eye coordination and fine motor skills

  • Impair visual functioning 

  • Impair judgment and decision-making skills

The more alcohol consumed, the worse brain function becomes and the greater the risk of serious road accidents and fatality.

Drugs & driving

Driving while under the influence of drugs is just as dangerous to yourself, passengers, pedestrians, and other road users as alcohol-impaired driving. Drugs have various effects on the brain and body, all of which can impair driving skills. 

For instance: [2]

  • Stimulants like cocaine and meth can cause hyperactivity which can lead to users becoming distracted, making rash, reckless or impulsive decisions

  • Opioids such as painkillers and heroin act as depressants which significantly reduce motor skills and reaction times

  • Marijuana can slow response and reaction times and also can cause visual hallucinations and perception alterations that make it hard to gauge distance and depth

  • Sedative drugs like alcohol, sleeping pills, and benzodiazepines can cause drowsiness, increasing the risk of falling asleep while driving and also reducing coordination

According to the National Highway Traffic Safety Administration’s (NHTSA) National Roadside Survey, more than 16% of weekend and nighttime drivers tested positive for illegal, prescription, or over-the-counter medications (11% tested positive for illegal drugs). In 2009, 18% of fatally injured drivers tested positive for at least one drug (illegal, prescription medication, and/or over-the-counter).

According to NSDUH data, men are more likely than women to drive under the influence of an illicit drug or alcohol. And young adults aged 18 to 25 are more likely to drive after taking a controlled substance than other age groups.

Related blog: Half of Car Accident Victims Had Drugs or Alcohol in Their System, Study Finds

How big is the problem?

Driving while under the influence of alcohol or other drugs is a widespread problem that is responsible for many deaths each year. Here are some statistics on the scope of the problem:

  • In 2016, 10,497 people died in alcohol-impaired driving crashes, accounting for 28% of all traffic-related deaths in the United States.

  • Of the 1,233 traffic deaths among children ages 0 to 14 years in 2016, 214 (17%) involved an alcohol-impaired driver.

  • In 2016, more than 1 million drivers were arrested for driving under the influence of alcohol or narcotics. That’s one percent of the 111 million self-reported episodes of alcohol-impaired driving among U.S. adults each year (figure below).

  • Drugs other than alcohol (legal and illegal) are involved in about 16% of motor vehicle crashes.

  • Marijuana use is increasing and 13% of nighttime, weekend drivers have marijuana in their system.

  • Marijuana users were about 25% more likely to be involved in a crash than drivers with no evidence of marijuana use, however, other factors such as age and gender may account for the increased crash risk among marijuana users.

What are the risks?

There are many risks associated with drinking while under the influence of alcohol or other drugs, including specific risks to young people, motorcyclists and pedestrians, and legal consequences that can have devastating consequences for impaired drivers.

Risk to self

  • At all levels of blood alcohol concentration (BAC), the risk of being involved in a crash is greater for young people than for older people

  • Among drivers with BAC levels of 0.08% or higher involved in fatal crashes in 2016, nearly three in 10 were between 25 and 34 years of age (27%). The next two largest groups were ages 21 to 24 (26%) and 35 to 44 (22%)

  • People who drive while under the influence of drugs or alcohol are far more likely to be involved in serious or fatal car accidents

Getting caught drinking or using drugs while driving can have serious and lasting legal, criminal, social, and employment consequences.

Related blog: States Rally To Ban “Gas Station Heroin” Tianeptine

Risk to others

  • Among motorcyclists killed in fatal crashes in 2016, 25% had BACs of 0.08% or greater.
  • Motorcyclists ages 35-39 have the highest percentage of deaths with BACs of 0.08% or greater (38% in 2016)

  • Pedestrians are more likely to be killed in a car accident involving a drunk or impaired driver

  • Drivers with a BAC of 0.08% or higher involved in fatal crashes were 4.5 times more likely to have a prior conviction for DWI than drivers with no alcohol in their system. (9% and 2%, respectively).

  • DWI’s and DUI’s can keep people from being able to get employed, especially in jobs that require driving

  • DUI’s and DWI’s can keep people from being able to get or afford car insurance 

  • DUI’s and DWI’s can be expensive, even for first-time offenders who will often need to pay for classes and legal fees

  • Multiple convictions can lead to permanent loss of your license

Driving while impaired (DWI) is a crime

Driving while impaired (DWI), also known as driving under the influence (DUI), drunk driving, or impaired driving is the crime of driving a motor vehicle while impaired by alcohol or drugs, including those prescribed by physicians.

With alcohol, a drunk driver’s level of intoxication is typically determined by a measurement of blood alcohol content or BAC. A BAC measurement in excess of a specific threshold level, such as 0.05% or 0.08%, defines the criminal offense with no need to prove impairment. In some jurisdictions, there is an aggravated category of the offense at a higher BAC level, such as 0.12%.

All 50 states and the District of Columbia have laws that specifically target drugged drivers. Almost one-third of states have adopted the per se standard that forbids any presence of a prohibited substance under The Controlled Substances Act in the driver's body while in control of the vehicle, without any other evidence of impairment. Others have established specific limits for the presence of intoxicating drugs, while still others follow a zero-tolerance rule with regards to the presence of intoxicating drugs in a person's system.

Being convicted of driving under the influence of drugs or alcohol can impact your life in ways you may not be aware of, including loss of employment, prevention of employment in certain jobs, higher insurance rates, serious financial setbacks, personal and family embarrassment, and possible incarceration.

How can deaths and injuries from impaired driving be prevented?

The best way to prevent deaths, injuries, and other lasting consequences from driving while impaired is to avoid taking these risks altogether. Never drink or use drugs and drive, and do not take rides from people who have been using drugs or alcohol, even if they insist they are safe to drive.

Effective measures include

  • Actively enforcing existing 0.08% BAC laws, minimum legal drinking age laws, and zero tolerance laws for drivers younger than 21 years old in all states
  • Requiring ignition interlocks for all offenders, including first-time offenders

  • Using sobriety checkpoints

  • Putting health promotion efforts into practice that influence economic, organizational, policy, and school/community action

  • Using community-based approaches to alcohol control and DWI prevention

  • Requiring mandatory substance abuse assessment and treatment, if needed, for DWI offenders

  • Raising the unit price of alcohol by increasing taxes.

What safety steps can individuals take?

Make plans so that you don’t have to drive while impaired by alcohol and/or drugs. 

For example:

  • Before drinking, designate a non-drinking driver when with a group

  • Don’t let your friends drive while impaired

  • If you have been drinking alcohol and/or using drugs, get a ride home, use a ride share service, or call a taxi

  • If you’re hosting a party where alcohol will be served, remind your guests to plan ahead and designate a sober driver. Offer alcohol-free beverages, and make sure all guests leave with a sober driver

Final thoughts

Drinking or using drugs and driving causes unnecessary injuries and deaths each year, and can have lasting or fatal consequences to both the driver and others. It is always advised to avoid driving when under the influence of alcohol or drugs, even if you believe you are safe or ok to drive. If you need help with a drug or alcohol problem, consider seeking help or attending a rehab program.