Last month brought news of yet another example of how driving under the influence of alcohol is dangerous and deadly: A car crash in Beverly killed the 20-year-old driver’s best friend. Police say the driver’s blood alcohol level was nearly three times the legal limit.

Few would dispute the risk of driving under the influence of alcohol. But what about the influence of marijuana?

Drugged driving is illegal, to be sure, but research into the effects of driving while high is still in its infancy. A recent review of the literature found that driving after using marijuana approximately doubles the chances of a crash, yet a rigorous 2015 study showed no increased risk of an accident.

While the jury is still out on the effects of driving stoned, a new study in the journal Health Education Research highlights a disturbing consequence of ingesting marijuana: Individuals who are high are more likely to think it’s OK to drive high or drunk, and they don’t think they’ll get caught.

“The effect of marijuana alone markedly increases the odds of a person thinking it is safe to drive drunk,’’ says study coauthor Jane Allen, a public health analyst at RTI International, a North Carolina-based nonprofit that does research for government and commercial groups. And since people commonly use drugs and alcohol simultaneously, “that is definitely a safety concern,’’ she says.

While evaluating a mass-media campaign to prevent drugged driving in Colorado — where there were 103 fatalities involving drugged drivers in 2013 alone — Allen and her colleagues at RTI put together an online survey for marijuana users in Colorado and Washington. At the last minute, Allen decided to include one more question on the survey: “Were you high or feeling the effects of marijuana or hashish when you took this survey?’’

Surprisingly, 16 percent of the 865 survey participants said, yes, they were high while taking the survey. And during the survey, those stoned individuals were more likely to agree with statements that they could safely drive under the influence of marijuana or alcohol than survey takers who weren’t high. They also had higher odds of saying they “probably would not get caught’’ while driving high and it is OK to drive “a little bit stoned.’’

Unfortunately, the results aren’t surprising. “People who are intoxicated sometimes have a lesser perception of the risks of certain behaviors,’’ says Allen. Alcohol shows a similar pattern as pot: Individuals who have been drinking also think they can safely drive under the influence.

The study is preliminary: It suggests that marijuana use can affect one’s perceptions about when it is safe to drive, yet it does not prove that being high actually increases the chance they’ll get behind the wheel high.

At present, cannabis-impaired driving is a minor public health problem compared to the problem of alcohol-impaired driving, says Wayne Hall, who studies addiction and public health at the University of Queensland in Australia and was not involved in the study. Still, he adds in an e-mail to the Globe, “One concern is that the scale of the problem will increase after cannabis legalization, unless measures are taken to discourage cannabis-impaired drivers from driving.’’

In November, Massachusetts residents will vote on a ballot question about whether to legalize recreational marijuana. The latest poll shows the Commonwealth is evenly divided about the question.

MEGAN SCUDELLARI