Mothers Against Drunk Driving rang in its 40th anniversary Saturday by addressing the dangers of driving while under the influence of marijuana.

According to a survey put out by MADD, one out of eight adults admitted to having driven after they had used marijuana. The organization said that 76% of those surveyed believe more people will begin driving while high as marijuana continues to be legalized for recreational use by states.

So far, 11 states have legalized marijuana use in all forms, and another 14 have decriminalized it.

“With two-thirds of the states now allowing some form of legal use of marijuana, MADD is concerned that a clear lack of understanding about the risks of marijuana-impaired driving threatens the safety of our nation’s highways,” MADD National President Helen Witty, whose 16-year-old daughter Helen Marie was killed by a drunk and marijuana-impaired driver, said in a news release.

“The survey highlights the confusion that exists and the shocking number of people who are consuming marijuana and driving.”

The survey also found that 41% are unsure or believe that people who regularly use marijuana are generally not impaired, making it safe to drive.

Twenty-six percent of those surveyed think that driving after recent consumption of marijuana is “not too concerning” or “not at all concerning,” with 43% of parents and grandparents surveyed saying they “never” discuss driving while high with their children or grandchildren.

Forty percent view driving while high as a serious crime, 27% say it is only a minor traffic offense, 4% think it is legal and 27% are unsure.

Despite not formally tracking marijuana-impaired drivers the same as they do with those who’ve used alcohol, MADD said that law enforcement officials have reported a steady rise in drivers who’ve been affected by marijuana usage.

The organization is embarking on a broad initiative to educate all U.S. drivers of the dangers of driving while high through program enhancements, public outreach and corporate alliances.

MADD commissioned global market research firm IPSOS to conduct a nationwide study of adults 18 and older from Feb. 14 – 18, 2020. The research aimed to understand the attitudes and awareness related to driving under the influence of marijuana, along with knowledge of the laws surrounding it.