Drivers say alcohol is bigger threat than pot

December 8, 2016


Marijuana legalization won at state ballot boxes in November amid broader public acceptance of a controlled substance that is still illegal under U.S. law. Although drivers don't consider marijuana to be quite as risky as alcohol when it comes to impaired driving, those who live in states that allow recreational use are more likely to view it as a highway safety problem than drivers in states without legalized use, a new Institute survey indicates.

Voters in California, Maine, Massachusetts and Nevada approved recreational use, and medicinal use was endorsed in Arkansas, Florida and North Dakota. Montana voters also expanded an existing medical marijuana law. Eight states and Washington, D.C., now have legalized marijuana for all uses, and 20 states have comprehensive medical marijuana programs. An additional 16 states permit limited access to marijuana products, typically low tetrahydrocannabinol, high cannabidiol extracts.

Marijuana is a Schedule 1 controlled substance under U.S. law. As states increasingly permit marijuana use, the proportion of drivers testing positive for marijuana and other drugs is on the rise, and perceptions about using marijuana are shifting (see "More drivers use marijuana, but link to crashes is murky," May 12, 2015). Six in 10 Americans now favor legalizing marijuana, compared with 12 percent in 1969 when polling firm Gallup first sought public opinion on legalization.

People overwhelmingly believe driving after drinking alcohol is a risk factor in crashes, but their views on getting behind the wheel after using pot aren't as clear. To see if opinions and behaviors related to driving after using marijuana and alcohol vary among states, IIHS scientists reached out to drivers 18 and older in Colorado, Oregon and Washington, which allow recreational use, and drivers in comparison states without legalized recreational marijuana use.

The phone survey was conducted between July and October 2015. It included representative samples of 1,508 drivers in the three states with legalized recreational use, 2,510 drivers in the comparison states of Idaho, Montana, Nebraska, Utah and Wyoming and 507 drivers in other states and the District of Columbia.

Nationally, drivers overwhelmingly supported legalizing marijuana for medical use (80 percent), and a substantial minority (42 percent) favored legal recreational use by people 21 and older.

Drivers in marijuana-legal states were twice as likely to report using marijuana within the past year and more often were drinkers than the comparison-state drivers. They also were more likely to report driving within two hours of using marijuana or drinking alcohol relative to the comparison states.

Drivers in the comparison states didn't deem marijuana as problematic as drivers in recreational use states. Forty-three percent of drivers in legal-use states said driving after using marijuana is a problem in their communities, compared with 28 percent in other states. Drivers who supported legalized recreational marijuana were much less likely to see driving after using marijuana as a problem than those who opposed legalization.

Nationally, driving after using marijuana wasn't perceived as negatively as driving after consuming alcohol, which the majority of respondents viewed as a problem in their communities.

Less than half of drivers surveyed considered marijuana's effects on driving to be about the same as alcohol's.

"The message that alcohol and driving is a dangerous combination is well-entrenched, but marijuana isn't viewed quite as negatively," says Angela Eichelberger, a senior research scientist at the Institute and the study's author. "As more states legalize marijuana use, we anticipate that perceptions about the drug's effects on driving may shift. Our survey serves as a baseline to track changes in opinions and self-reported behaviors over time."

Percent of drivers who said driving after using alcohol or pot is a problem in their community

U.S. laws legalizing some uses of marijuana

December 2016

Map of U.S. state legalizing some uses of marijuana, as of December 2016

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