Driving High? Experts Can’t Figure Out How to Measure Impairment

We advocate for safe driving, but if you are driving high, then how much is too much? That is the question that the authorities across states that legalized recreational weed are trying to figure out. As of now, it is a very subjective test due to how long marijuana stays in your system and the way that you decide to consume cannabis.

If you eat an edible, hop in the car and then get pulled over for driving high and end up in jail for DUI, then the levels of THC in your body will increase as your body breaks down the edible. However, if you smoke a joint or take a pull off the vape pen and then get behind the wheel, you have a higher probability of driving high and getting a DUI.

As of now, the authorities are still trying to figure out the best way to test impairment and as the industry grows, more time and money will be spent on figuring out the best way to keep people on the roads safe.

The number of fatal Washington crashes involving drivers with marijuana in their system rose to 79 last year — more than double that of 2012 when voters legalized its recreational use.

In Yakima County, however, the number has remained essentially unchanged at an average of about five a year, according to the state Traffic Safety Commission.

But experts caution the statistics focus only on fatal crashes and don’t provide a complete picture of the impact pot is having on road safety.

When issuing impaired driving citations, most police agencies don’t differentiate between alcohol, pot or other drugs. They’re simply categorized as DUIs.

As a result, data regarding marijuana- impaired drivers isn’t complete. No statewide data is kept on serious injury accidents involving marijuana because of reporting inconsistencies by local police agencies, according to the safety commission.

From a traffic safety standpoint, the state wasn’t ready for the legalization of recreational marijuana, said Nathan Weller, a Pullman-based consultant helping Washington State University with a marijuana-impairment study.

“The amount of challenges that went along with it was unknown at the time (of voter approval) and now we’re playing catch-up,” he said.

Most officers use a standard field sobriety test that initially focuses on impairment rather than determining whether a driver is over the legal limit, said Washington State Patrol Sgt. Brandon Villanti, who works in the impaired driving unit in Seattle.

“We look for impairment and inability to provide attention, motor skills, ability to operate a motor vehicle,” he said. “So our officers are not making an arrest on legal limit but on impairment, and that is confirmed with a blood or breath test.”

But those tests may not be adequate considering the variables of involving marijuana intoxication. Eating pot products can take one to five hours before the peak affect kicks in, compared to the more immediate affect produced by smoking it. That can make it difficult to determine the level of impairment at the time of an accident, Weller said.

For example, someone who smoked it may have a low level of THC in their blood an hour later even though they were high when they were driving, he said.

A person who ingests pot may not have been high at the time of driving but later test positive at a police station, Weller said.

And pot is hard for users to regulate compared with alcohol. For many people it’s safe to drive one hour after a drink, two hours after two drinks, and so on because the amount of alcohol in each drink is regulated.

Participants described getting higher off some products that claimed to have lower THC concentrations than others, he said.

“It’s a rabbit hole right now,” Weller said. “We’re just scratching the surface.”

Researchers in the WSU study are working on developing a Breathalyzer similar to ones used to detect alcohol, he said.

Similar work is being done in Colorado, where fatal crashes involving marijuana have shot up since legalization there in 2012.

Villanti said there are times when a blood test may not reveal the impairment an officer sees on the road. Depending on the case, a drug recognition expert may be brought in to investigate. There are 200 recognition experts in the state who can not only identify a substance of drug but calculate what a person’s level of intoxication was hours before a test, he said.


read more at 420intel.com

Show More

Richard Lowe

Richard Lowe is a 14-year veteran of the financial sector with licenses as a commodity broker (Series 3) and investment advisor representative (IAR Series 65). Along with a focus on raising capital for the firms he was employed with, he also wrote and edited much of the content published by them. He holds a BA in Journalism from the University of Massachusetts. He has been a longtime advocate for marijuana legalization due to the social injustices associated with marijuana prohibition and the strong potential for the medicinal benefits of cannabis.

Related Articles

One Comment

  1. The Drug and Alcohol Crash Risk report, produced by the Department of Transportation’s National Highway Traffic Safety Administration, found that while drunken driving dramatically increased the risk of getting into an accident, there was no evidence that using marijuana heightened that risk. In fact, after adjusting for age, gender, race and alcohol use, the report found that stoned drivers were no more likely to crash than drivers who were not intoxicated at all.
    It’s worth taking a closer look at that 2015 NHTSA study, because federal officials put a lot of stock in it as “the first large-scale [case control crash risk] study in the United States to include drugs other than alcohol.” Data was collected from more than 3,000 crash-involved drivers and 6,000 control drivers (not involved in crashes) over a 20-month period in Virginia Beach, Virginia. The data was fresh and solid: Research teams responded to crashes 24 hours a day, 7 days a week. Drivers were considered THC-positive if they tested for active THC, not for non-impairing metabolites still in their blood days or weeks after consumption.
    While THC-positive drivers were 5{b9c41f62a37c687b31b667cf69204c41d59060d4b370c48d31ec094649de4955} more likely to be involved in a crash, the researchers found that drivers who’d taken an opioid painkiller had a 14{b9c41f62a37c687b31b667cf69204c41d59060d4b370c48d31ec094649de4955} greater risk of crashing. Here’s a chart from that NHTSA study comparing THC (marijuana) with opioids (narcotic analgesics) and other drugs:
    Those levels of increased risk were tiny, however, compared to the risk involved with alcohol. Drivers within the legal range of blood alcohol level as registered by a breathalyzer (BrAC) were found to be 20{b9c41f62a37c687b31b667cf69204c41d59060d4b370c48d31ec094649de4955} to 222{b9c41f62a37c687b31b667cf69204c41d59060d4b370c48d31ec094649de4955} more likely to be involved in a crash. At .08 BrAC, the legal limit, the risk increased to 293{b9c41f62a37c687b31b667cf69204c41d59060d4b370c48d31ec094649de4955}. At 0.15 BrAC, drivers were more than 12 times (+1118{b9c41f62a37c687b31b667cf69204c41d59060d4b370c48d31ec094649de4955}) more likely to be involved in a crash than a sober person. Here’s a chart from that same study, calculating the increased risk of crashing at rising blood alcohol levels:
    By comparison, a driver who has taken penicillin is 25{b9c41f62a37c687b31b667cf69204c41d59060d4b370c48d31ec094649de4955} more likely to be involved in a crash. Drivers carrying two or more passengers are 120{b9c41f62a37c687b31b667cf69204c41d59060d4b370c48d31ec094649de4955} more likely to crash. Drivers using mobile phones to talk or text are 310{b9c41f62a37c687b31b667cf69204c41d59060d4b370c48d31ec094649de4955} more likely to crash.
    A separate NHSTA study (“Marijuana And Actual Driving Performance”) further conceded it’s “difficult to establish a relationship between a person’s THC blood or plasma concentration and performance impairing effects … Drivers with high concentrations showed substantial [impairment], but also no impairment, or even some improvement.” In other words, cannabis affects different drivers in different ways, depending on a number of factors.

Leave a Reply

Back to top button