- The Washington Times - Thursday, April 28, 2022

States are legalizing marijuana use at a stunning pace, sparking a race to better train police officers for traffic stops and develop technologies that can help them determine whether motorists are driving while high.

Efforts to create a roadside breath test for marijuana, akin to portable tests for alcohol, have lagged behind state legislatures’ rush to legalize recreational use of the drug. Yet new devices coming to the market are enthusing state officials and law enforcement agencies who need a leg up in detection.

“We are seeing a lot of different substances causing impairment on our roads. The top two are cannabis and alcohol, so it makes sense to have a device for each. Right now, we only have one for alcohol, and that can limit law enforcement’s ability to conduct a roadside sobriety test,” said Sam Cole, a traffic safety spokesman at the Colorado Department of Transportation.

Alcohol’s impact on driving has been analyzed for decades, but the study of marijuana’s impact is more nascent. That means detecting and prosecuting motorists who drive under the influence of cannabis is playing catch-up with DUIs for alcohol.

Police often use portable breath tests for alcohol at the roadside before they obtain more sensitive Intoxilyzer results at the station to confirm results and use them in court. Police must rely on roadside observations and a blood test or — in some states — a urine screen to confirm whether a driver is arrested on suspicion of being under the influence of marijuana.

Hound Labs, based in Oakland, California, said it has developed a breath test that can measure cannabis use in recent hours — a key piece of the puzzle in determining whether a motorist is impaired or simply has remnants of the drug in their system.

Alcohol can be detected in the bloodstream for up to six hours. Marijuana can be detected for several days in an infrequent user and a month or more in heavy users, according to studies.

“Currently, law enforcement uses the combination of observations, sobriety tests and objective alcohol breathalyzer results to make decisions at the roadside about a driver’s recent alcohol use. When assessing recent cannabis use, law enforcement is missing objective cannabis breathalyzer results,” said Dr. Mike Lynn, CEO of Hound Labs. “We will be able to provide the objective results that law enforcement needs to make more informed decisions at the roadside.”

Dr. Lynn said many law enforcement agencies have inquired about the devices, which could be deployed later this year, though decisions on whether Hound marijuana breathalyzer test results can be admissible at trial will be up to the courts.

Cannabix Technologies of Vancouver, British Columbia, and Vox Biomedical of Massachusetts are other key players in the race to develop a reliable breath test for marijuana.

Law enforcement is eyeing new tools as the U.S. takes a marked turn toward permissive laws for using marijuana. Advocates for legalization say criminalizing possession and use tends to fall on the poor and people of color and the drug should be treated similarly to alcohol, which is legal for those 21 and older.

Colorado and Washington state became the first places in the U.S. to legalize recreational marijuana in 2012. Since then, 16 states and the District of Columbia have joined them. New Jersey launched a retail program last month.

In November, voters in Maryland will decide whether to legalize recreational marijuana use for people 21 or older as of July 2023. A “yes” vote on the ballot question would also direct the Maryland state legislature to enact laws for the use, distribution, regulation and taxation of marijuana.

The Democratic-led House of Representatives recently passed a bill to legalize marijuana nationwide, but the legislation faces a higher bar in the evenly divided Senate.

Increasingly permissive marijuana laws have thrust several thorny issues into the spotlight. New Jersey is debating a part of its marijuana program that allows police to use legally purchased pot while off duty. There also are legal questions about how “dram shop laws,” which hold people liable for overserving customers with alcohol, should be applied to marijuana sellers.

Yet fear of a surge in marijuana DUIs on top of alcohol-fueled incidents is one of the most prominent concerns.

Road signs from California to the nation’s capital remind drivers that while cannabis might be legalized, driving while impaired by the substance is illegal. The Ad Council and National Highway Traffic Safety Administration released a public awareness ad this year featuring young people delaying a camping trip because all of them were using marijuana and none of them was equipped to drive.

“If you feel different, you drive different,” the narrator says, deploying a tagline the NHTSA has used since 2018.

Driving while impaired by marijuana or alcohol is illegal in all 50 states. Efforts to get a handle on cannabis have been held back by the differences in how the substances interact with the body and the difficulty in determining a nexus between marijuana use and poor driving.

The longer dwell time, or half-life, of cannabis in human circulation “versus the high volatility of alcohol is the major challenge in figuring out whether the presence of THC in breath or saliva is due to a recent consumption or whether this occurred days prior,” said Shalini Prasad, a professor of bioengineering at the University of Texas, Dallas, who has researched the topic.

THC refers to tetrahydrocannabinol, which is largely responsible for the effects of marijuana on the mental state. Some states need only to prove the consumption of marijuana to prosecute an impairment case, and others have per se laws that determine whether a person is impaired at or above a certain threshold of detected THC.

AAA said states prosecuting marijuana DUIs should avoid per se laws — people have different levels of impairment at set amounts of THC — and use a “permissible inference” standard that combines any detectable amount of active THC alongside evidence from roadside sobriety tests and the opinions of drug recognition experts.

AAA said better enforcement is sorely needed. The motor clubs federation cited a study published in a medical journal in November that found the percentage of U.S. road fatalities involving cannabis rose from 9% in 2000 to 21.5% in 2018. Those involving cannabis plus alcohol increased from 4.8% in 2000 to 10.3% in 2018.

The nonprofit organization also pointed to data showing an estimated 8.8% of Washington state drivers involved in fatal crashes were positive for THC before recreational use was legalized in 2012. That rate rose to 18% from 2013 to 2017.

Among other reforms, AAA wants more funding for drug recognition experts, toxicology labs, more public awareness campaigns and separately categorized DUIs for drugs and alcohol so law enforcement is more detailed in its reporting.

“State efforts to curb drugged driving vary considerably, but AAA is lobbying for a range of countermeasures in states that have or likely may legalize cannabis for recreational use,” said Jake Nelson, AAA’s director for traffic safety advocacy and research. “We believe these measures help create environments that allow for better identification and adjudication of drugged drivers. This is an important step towards creating a culture among motorists that using and driving should be avoided.”

Mark Meredith, a police practices, premises security and drug recognition expert at Robson Forensic in California, said until the courts recognize the validity of marijuana breath tests, their readings may not be used in legal proceedings.

“You would still need the urine or the blood to back it up,” he said.

The roadside test could still be valuable, particularly in rural areas that need to understand whether there is probable cause for further investigation.

“We continue to have law enforcement inquire about purchasing Hound marijuana breathalyzers because they are interested in an objective test that will provide negative results unless the person used cannabis within a few hours of the test,” Dr. Lynn said. “This might seem surprising to some, but the negative results are important because they corroborate the statements of drivers or employees who say they have used legally and responsibly, for example, at a party the previous night. Testing breath is the only way to identify cannabis use within a few hours of the test and the best way to balance safety and fairness.”

AAA also said a roadside test would help police decide whether they need to call in a drug recognition expert to assist on the case or request a search warrant to collect a blood sample for drug testing.

Alongside technology, police are putting more recruits into drug-recognition training.

“It is fairly simple to determine if someone is under the influence of alcohol. Marijuana, on the other hand, is a big difference. You need that bit of an edge, or more training to be able to recognize the signs and symptoms,” said Mr. Meredith, who spent nearly three decades in law enforcement in California.

One of the more obvious differences between alcohol and marijuana cases in a roadside stop is how the car or driver smells. 

A more subtle sign that requires training is the lack of convergence (LOC), when officers perform a test that involves holding a finger a certain distance from a driver’s face and slowly and consistently bringing it closer to the driver’s nose.

“What you see with people under the influence of marijuana is one or both eyes is not able to go cross-eyed,” Mr. Meredith said.

He said people under the influence of marijuana also are more likely to have an elevated pulse or dilated pupils.

Colorado has not seen a marked increase in impaired driving deaths caused by cannabis, with the number of fatalities involving a driver with at least 5 nanograms of THC in the blood — its threshold for determining impairment — fluctuating in the most recently documented years, including 52 in 2016, 35 in 2017, 42 in 2018, 59 in 2019 and 48 in 2020.

DUI arrests are increasing as officers get better at detection.

“Legalization allowed us to ramp up training of law enforcement to increase their skills on detecting impairment beyond alcohol, including cannabis. A majority of Colorado State Troopers now have specialized training in drug detection, known as Advanced Roadside Impaired Driving Enforcement. This may explain any increases in cannabis DUIs,” Mr. Cole said.

The Colorado legislature is exploring the use of devices to assess the impairment of motorists by substances other than alcohol during roadside testing.

However, he said, “no testing device is currently allowed by Colorado statute or approved by law enforcement.”

• Tom Howell Jr. can be reached at thowell@washingtontimes.com.

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