BOISE – Alcohol and marijuana are the most commonly used drugs in the United States, and according to new research by AAA, drivers who use both are significantly more likely to have dangerous driving habits.

In AAA’s 2019 Traffic Safety Culture Index, survey participants were asked about their behaviors from the past 30 days.  While 50% of respondents said that they did not drink or use marijuana before driving, 40% reported using alcohol, 4% used marijuana, and 5% used both.

In AAA’s research, drivers in the ‘both’ category were much more likely to admit driving while they believed that they were impaired by drugs or alcohol.  They also reported engaging more frequently in risky driving behaviors than those who used alcohol alone:

  • Speeding on residential streets (55%) vs. alcohol-only (35%)
  • Aggressive driving, such as sudden lane changes and tailgating (52%) vs. alcohol-only (28%)
  • Intentional red-light running (48%) vs. alcohol-only (32%)
  • Texting while driving (40%) vs. alcohol-only (21%)

According to government data, nearly 140 million people aged 12 or older reported drinking alcohol in the past month, and 43.5 million reported using marijuana in the last year.

“Anecdotally, it’s possible that substance misuse may have increased during the pandemic,” says AAA Idaho spokesman Matthew Conde.  “Impaired driving puts everyone at risk, and based on our research, combining marijuana and alcohol use only seems to amplify the problem.”

AAA says that just 27 percent of drivers think they’ll be caught by the police while driving high, compared with 68 percent of drivers who think they’ll be caught while under the influence of alcohol.  But AAA reminds motorists that impairment is impairment, no matter the cause.

According to the Idaho Transportation Department, impaired driving crash fatalities increased in 2019 by 27 percent to 99 deaths.  About 44 percent of the state’s crash fatalities were from impaired driving.

“Neighboring states have taken different approaches to recreational and medical marijuana, but it’s never safe to use while driving,” Conde said.  “If you’re going to drink or use drugs, please don’t drive, and it’s also important to check with your health care provider about the possible dangers of driving while using prescription medications.”

17 states and Washington, D.C. have legalized recreational marijuana, and 19 states have legalized medical use.  Another 15 states are considering some form of medical or recreational legalization.

Table 1. Prevalence of Self-Reported Impaired Driving Behaviors in Relation to Alcohol and Marijuana Use in a Sample of 2,710 U.S. Drivers, Weighted to Represent U.S. Driving Population Ages 16 and Older.

  No Alcohol or Marijuana Use Alcohol Use Only Marijuana Use Only Both Alcohol and Marijuana Use
Total Respondents 1,434 1,036 103 137
DUI*—Alcohol N/A 14% N/A 39%
DUI—Marijuana N/A N/A 37% 52%
DUI—Prescription Drugs 4% 4% 14% 25%
Riding w/ intoxicated driver 5% 12% 13% 37%
Drowsy driving 21% 25% 22% 35%

Note: Percentages include responses of “a few times,” “fairly often,” or “regularly.”

*  DUI refers to self-reported driving under the influence, not being charged with a DUI by law enforcement

Table 2. Prevalence of Self-Reported Risky Driving Behaviors in Relation to Alcohol and Marijuana Use in a Sample of 2,710 U.S. Drivers, Weighted to Represent U.S. Driving Population Ages 16 and Older.

  No Alcohol or Marijuana Use Alcohol Use Only Marijuana Use Only Both Alcohol and Marijuana Use
Total Respondents 1,434 1,036 103 137
Read text b 24% 30% 31% 53%
Type/send text b 16% 21% 24% 40%
Speed—highway b 34% 43% 46% 55%
Speed—residential b 28% 35% 46% 55%
Running a red light a 28% 32% 38% 48%
Aggressive driving a 21% 28% 41% 52%
Drive w/o seatbelt b 11% 11% 16% 18%

a Percentages include responses of “a few times,” “fairly often,” or “regularly.”

b Percentages include responses of “just once,” “a few times,” “fairly often,” or “regularly.”