This is something our Los Angeles marijuana DUI attorneys have argued for years. Now, this same conclusion was backed by a federally-funded study. Backed by a grant from the National Institute of Justice, researchers tested the THC levels of 20 individuals who either vaporized or ate varying levels of THC. They were then subjected to numerous cognitive and field sobriety tests, similar to what are used by law enforcement.

The groups that received higher doses of THC (above 5 mg) were adversely impacted in terms of their sobriety – their psychomotor skills were visibly impaired – the level of THC in their blood and other biofluids didn’t reliably reflect that. Thus, the amount of THC in one’s blood was not a good indicator of marijuana intoxication.

There is little question that marijuana impairment does impact the skills needed for safe driving, including reaction time and spatial awareness. However, what the researchers determined was the amount of THC in the subjects’ blood, urine and saliva failed to correlate with how well they performed in field sobriety tests when they were clearly intoxicated – no matter how much THC they actually ingested.

What this does is raise substantial questions about per se marijuana DUI laws that are in place in six states, including nearby Nevada and Washington. These laws prohibit people from operating a vehicle if they more than a certain amount of THC in their blood. California does not have a per se limit when it comes to driving under the influence of marijuana.

The results of the study come as no surprise to our Los Angeles marijuana lawyers, nor are they a shock to longtime marijuana rights advocates. The fact is, the science was never there to support per se laws for marijuana impairment. Instead, these laws are based on arbitrary limits.

Beyond this, though, the researchers found that several, standard field sobriety tests – standing on one leg, balancing, walking and turning – weren’t affected by one’s cannabis impairment for any of the study participants, regardless of how much THC they ingested. In other words, many of the same tests used to determine if someone was driving under the influence of drugs or alcohol were not effective in singling out marijuana impairment.

Last year, the Journal of the American Medical Association (JAMA) published a study that indicated low levels of CBD don’t have any real impact on driving. Beyond that, a modest level of THC had a “modest in magnitude” impact that was similar to those who had a blood-alcohol concentration of about 0.05 percent. Even congressional researchers concluded three years ago in a published report that we don’t have conclusive evidence about the levels at which cannabis impairs one’s ability to drive. We also know that in states where marijuana has been legalized for recreation, traffic fatalities have not risen.

All this said, even most supporters of marijuana rights are careful to warn against driving under the influence of any substance, marijuana included. But it’s determining what “under the influence” means with regard to cannabis in a legal sense that has been throwing so many for a loop.

If you have been arrested for a marijuana DUI in Southern California, our dedicated marijuana DUI defense lawyers can help.

The Los Angeles CANNABIS LAW Group represents growers, dispensaries, ancillary companies, patients, doctors and those facing marijuana charges. Call us at 949-375-4734.

Additional Resources:

Testing People For Marijuana Impairment Based On THC Levels Is ‘Not Reliable,’ Federally Funded Study Finds, June 4, 2021, By Kyle Jaeger, Marijuana Minute

A new study conducted by the Insurance Institute for Highway Safety conducted a recent study of some 2,000 drivers in Washington state, California’s northern neighbor which also allows recreational marijuana use, and discovered approximately 14 percent of those with children in their vehicle tested positive for THC, which of course is the component of cannabis that gets users high. NBC News reported was far higher than the number who tested positive for alcohol, which was a about 0.2 percent of those with children in their vehicles.

It’s worth noting, of course, that alcohol and marijuana have two very different effects on the body, which means these figures are somewhat alarmist in nature. If it were possible to test the number of drivers who had consumed alcohol at some point in the last several days or weeks, no doubt the actual number of those would be much higher, and we’d have more of an apples-to-apples comparison.

While alcohol is processed quickly through the bloodstream, marijuana (and in turn, THC) lingers. In effect, a person who tests positive for marijuana may not necessarily be impaired, but merely has consumed the drug at some point in the last few days or even weeks.

Los Angeles cannabis DUI attorneys know that determining who was actually “stoned” behind the wheel is much trickier because of how long marijuana stays in the body – even long after the high has worn off.

Of course, it’s true that marijuana interferes with one’s driving skills. As noted in a 2009 study published in The American Journal on Addictions, marijuana absolutely can acutely impair one’s reaction time and other cognitive functions critical to driving. They did find that the effect between individuals varies significantly compared to alcohol due to differences in tolerance, the way the drug is consumed and variations in dosing.

THC-impaired drivers did often try to compensate – and rather effectively – for impairment by utilizing strategies like driving more slowly, passing less frequently and allowing more space between their vehicles and those ahead. However, whatever benefit is gained from that is tossed if one also combines THC with alcohol.

That doesn’t mean you’re going to catch a break from county or city police in Los Angeles if you’re deemed impaired by marijuana according to statute.

Driving Under the Influence of California Cannabis

California Vehicle Code 23152(f) prohibits driving under the influence of marijuana. It is a crime to do so, and penalties are the same as they would be for driving under the influence of alcohol. (Proving intoxication tends to be tougher, though, for the reasons aforementioned.)

For a first-offense, defendant can serve up to six months in jail with a maximum fine of $1,000, a 9-month stint in DUI school and 10 months of a suspended and/or restricted license. Penalties will be more severe if you have a minor in the vehicle.

To be impaired means to have one’s physical and/or mental capacities impaired by the drug(s) to the point he/she is not able to operate a motor vehicle with the caution of a sober person using ordinary care in similar circumstances. This is a largely subjective standard. While the level of THC in one’s system can be used as evidence in a California marijuana DUI case, it is not proof-positive. An increasing number of departments in the state have trained/hired drug recognition experts on their police forces specifically to boost credibility of officer testimony.

As our Los Angeles marijuana DUI lawyers can explain, simply sitting behind the wheel of a car – even with the engine running – in and of itself isn’t proof of “driving,” for purposes of the statute, though it can be used as circumstantial evidence.

How Much Does Marijuana Truly Contribute to California Traffic Crashes?

It’s tough to quantify just how much of a role marijuana plays in motor vehicle accidents in California – or anywhere – because:

• Those who test positive for THC in blood or urine aren’t necessarily high (and there isn’t yet an objective biological test for impairment);
• Those who have marijuana in their system often have consumed multiple substances.

Part of what makes it confusing for drivers in states that allow legal marijuana is that there is no set amount or what is a safe amount to consume before driving.

One slogan being touted by the U.S. National Highway Traffic Safety Administration is that, “If you feel different, you drive different.” That’s a good notion to keep in mind, but it’s not the criminal standard for impairment on California roads. The Los Angeles CANNABIS LAW Group represents growers, dispensaries, ancillary companies, patients, doctors and those facing marijuana charges. Call us at 949-375-4734. Additional Resources: Many drivers who test positive for marijuana have a child in the car, survey finds, April 25, 2019, NBC News More Blog Entries: Los Angeles, West Hollywood, Weigh Allowing Pot Smoking in Public, March 12, 2019, Los Angeles Marijuana DUI Lawyer Blog

Both proponents and opponents of greater marijuana access laws generally agree on the fact that those who are under the influence of the drug shouldn’t be operating a motor vehicle. It’s well-established that THC, the psychoactive substance in marijuana, has the potential to negatively impact driver performance (i.e., cognitive and motor abilities) and thus traffic safety. Where these two groups diverge is how we address this issue.

Understandably, lawmakers and traffic safety advocates want a solution that will keep marijuana-impaired individuals off the road. But the solution they reached is one that doesn’t make the roads safer and unfortunately may ensnare innocent people in criminal cases.

A per se limit is a designated amount of the substance in question which, if exceeded, is supposed to indicate impairment.

Per se limits work when it comes to alcohol impairment. Everywhere you go in the country, the standard limit for one’s blood alcohol limit is 0.08 units of mass alcohol per volume of blood. So there are 0.08 grams of alcohol for every deciliter of blood. The reason this system works for alcohol impairment is that alcohol is processed rapidly by the system. If someone tests high on that scale, chances are good that individual is not sober.

But marijuana is processed differently. THC may build up in one’s system and remain over time – even long after the cognitive and psychomotor effects of the drug have worn off. As our Los Angeles marijuana defense lawyers know, this means a person who regularly uses marijuana – say, for medicine – may have a high level of THC in their blood, but they aren’t in fact impaired.

Ultimately, per se driving limits make it a crime to operate a car while they have any detectable amount of marijuana in their system – even absent any other proof the driver was impaired.

The AAA study wanted to determine whether there was any proof that per se laws to prevent marijuana impaired drivers made sense. Researchers analyzed the records of 602 drivers who were arrested for DUI and in which only THC was present in the driver’s blood. Researchers also looked at 349 control samples and another 4,799 drivers arrested for DUI who tested positive for one or more cannabinoid.

They found that in comparison to the drug-free controls, those who were arrested for driving under the influence of marijuana tested more poorly in a number of psychophysical tests (finger-to-nose, one-leg-stand, walk-and-turn, etc.). However, in terms of figuring out a quantitative threshold for per se laws, researchers determined one “cannot be scientifically reported.”

These findings are in line with the U.S. National Highway Traffic Safety Administration (NHTSA) which has conceded that establishing a relationship between a person’s THC blood or plasma concentration and impairment is “inadvisable” when it’s based solely on the amount of THC in a person’s system.

The Los Angeles CANNABIS LAW Group represents growers, dispensaries, collectives, patients and those facing marijuana charges. Call us at 949-375-4734.

Additional Resources:

An Evaluation of Data from Drivers Arrested for Driving Under the Influence in Relation to Per Se Limits for Cannabis, May 2016, AAA Foundation for Traffic Safety

More Blog Entries:

Driver Allegedly High on Medical Marijuana Caused Crash Resulting in Trooper’s Death, June 1, 2016, L.A. Marijuana DUI Arrest Lawyer Blog