By Aaron Crowe

Drivers who use marijuana are at a much lower risk for car crashes than drivers who use alcohol, according to a study by the National Highway Traffic Safety Administration.

When adjustments for age, gender, ethnicity and alcohol consumption were taken into account, drivers who were high on marijuana were no more likely to get into a crash than drivers who hadn’t used drugs or alcohol before driving.

“When compared to alcohol, it’s closer to being sober than being drunk,” says Sam Tracy, former chairman of Students for Sensible Drug Policy, on smoking weed.

The measurable presence of THC — tetrahydrocannabinol, the chemical in marijuana that’s most responsible for its psychological effects — doesn’t link to impairment in the same way alcohol does.

Any drugs or alcohol impair drivers, however, and neither the NHTSA study or any advocates of marijuana say drivers should use drugs or alcohol before driving.

The study found that marijuana smokers are 25 percent more likely to be involved in an accident than a sober driver. That increased risk may be due in part because marijuana users are more likely to be in groups at higher risk of crashes, such as young men.

Drunk drivers with a Blood Alcohol Level of 0.08 percent — usually one drink for a person of average weight — are four times more likely to get in a crash than a sober driver. A BA level of 0.15 percent led to being 12 times more likely to crash.

“It (marijuana) doesn’t affect motor control as much as alcohol does,” Tracy says.

Good news for marijuana advocates

The results help point out that stopping use of alcohol before driving should be more of a focus than marijuana, says Paul Armentano, deputy director of NORML, a group working to reform marijuana laws.

“Alcohol is far and away the leading cause of accidents,” Armentano says.

Instead of fighting the legalization of marijuana, society should be focused on preventing alcohol-related car crashes, he says.

“An adult should be permitted to use marijuana in the privacy of their own home and not face any penalties for it,” Armentano says.

Studies aren’t conclusive

While the NHTSA said its findings were consistent with other well controlled studies, other studies, however, have found that in states where medical marijuana is legalized, more drivers are testing positive for the drug who were involved in fatal car accidents.

Last year, Columbia University’s Mailman School of Public Health reported that fatal crashes involving marijuana tripled during the previous decade. If the trend continues, in five or six years non-alcohol drugs will overtake alcohol to become the most common substance involved in impaired driving deaths, a researcher concluded.

The NHTSA study and other studies aren’t conclusive about the safety of marijuana use, and the takeaway shouldn’t be that it’s OK to smoke marijuana and drive because it’s safer than driving drunk, says Dr. Damon Raskin, medical director and board certified addiction expert for Cliffside Malibu Treatment Center in Malibu, Calif.

“It may be less likely than alcohol, but not less likely than smoking no marijuana at all,” Raskin says.

The NHTSA study doesn’t conclude that marijuana is safe, only that it’s safer than drinking and driving, Raskin says. It’s a drug that needs to be regulated, he says.

“Marijuana is a very dangerous drug to our youth,” he says, “and people who get hooked on marijuana at a very young age could have problems later in life.”

THC level may not measure impairment

THC stays in a person’s blood system for days or even weeks after using marijuana. Someone who tested positive for marijuana use after a car crash may have used the drug weeks ago, while the effects may only last a few hours. Marijuana use may not have been a factor if they smoked it weeks, days or even hours ago.

In Colorado, a state where marijuana is legal, highway fatalities are at near-historic lows.

Since the risk of crashing while under the influence of marijuana is closer to the risk level of texting while driving, it should be punished in the same way, Tracy says, with a fine of a few hundred dollars. A drunk driving offense can lead to fines of thousands of dollars and other restrictions.

Lower highway fatalities in Colorado may be because marijuana users are more likely to realize they’re impaired than drunk drivers are, Tracy says, and either stay off the road or drive slower.

“If I had to share the road with someone who was drinking alcohol or had just smoked marijuana, I’d take the person who smoked marijuana,” he says.