New Study Cautions States on the Impact of Marijuana
Written By Lucas Kibby, CleanFleet
According to the National Cooperative Research and Evaluation Program’s (NCREP) federal safety study, Impact of the Legalization and Decriminalization of Marijuana on the DWI System, state institutions involved in drugged driving law enforcement, prosecution, probation, toxicology, and data sharing will face growing pressure as marijuana legalization continues to spread.
The current public perception seems to be “Pot is legal, so it must be safe,” when in reality “marijuana today is different from the marijuana of yesterday,” as one Oregon expert in the study noted.
During an earlier 2013-2014 National Roadside Survey (NRS) of Alcohol and Drug Use by Drivers, the National Highway Traffic Safety Administration (NHTSA) collected breath, oral fluid, and blood samples to detect alcohol and drug use by weekday daytime and weekend nighttime drivers.
In 2013, nearly one in four drivers tested positive for at least one drug that could affect safety and the percentage of weekend nighttime drivers who tested positive for drugs (using the same criteria that had been used in a similar 2007 study) had increased to 20 percent. In fact, the percentage of drivers with marijuana in their system increased by nearly 50 percent (from 8.6% in 2007 to 12.6% in 2013-2014).
This led to the latest panel study on the Impact of the Legalization and Decriminalization of Marijuana on the DWI (driving while impaired) System.
We will walk through three areas of the study. To read the full report, click here.
Impact on Highway Safety
According to the report, they considered the impact of drug positive driving on highway safety. NHTSA’s National Roadside Studies show that the presence of THC among drivers has increased, and THC positive driving now exceeds alcohol positive driving.
However, the impact of THC on crashes is not clear. Fatal crashes have declined in many States, including Colorado and Washington, and NHTSA’s Crash Risk study did not show elevated crash risk for THC positive drivers when adjustments were made for demographic factors known to be associated with high crash risk.
Major issues include data, funding, training, studies of the impacts of marijuana-positive driving, and evaluations of countermeasures. States should either form or expand the scope of existing task forces, advisory committees, or leadership teams to focus on these issues. Plans to address drugged driving should be included in Highway Safety Plans (HSPs), which are submitted to NHTSA, and Strategic Highway Safety Plans (SHSPs), which are submitted to the Federal Highway Administration.
Legalized sales of marijuana can generate a great deal of State revenue, and if allowed by statute, funding can be used to support TSRPs, experienced prosecutors, DWI courts, law enforcement training and equipment, toxicology laboratory staffing, equipment, and court testimony costs. A representative from Washington State on the expert panel noted that there is no funding stream until sales of marijuana begin, and existing funds tend to already be committed.
To date, there is little regulation or oversight over the sale of marijuana, especially medical marijuana. Its use is expected to rise, even in States that permit recreational marijuana.
Impact on Toxicology
Toxicology, according to the report, is the scientific study of chemicals, drugs, and other substances, and how a person or other living thing reacts to them. Toxicology plays a critical part in the criminal justice system, especially in drug-impaired driving cases. According to a toxicologist who served on the expert panel, “Toxicologists rely on research and, unfortunately, there currently isn’t much.” Accordingly, many cases involve competing testimony about toxicology, “expert versus expert.”
Chronic users can have high levels of marijuana present in their bodies, but they may not be impaired. Data is often misused. For example, a metabolite of THC is “inactive” but its presence may incorrectly be used to “show” impairment.
Laboratories desperately need more equipment and more staff to run tests and provide testimony. In Washington State, the number of tests each year increased from 4,500 positive tests to 6,000 positive tests by lowering the “cut-off” threshold for being considered positive. In California, only 25 percent of offenders are tested for THC.
Laboratories across the country follow very different practices, such as which drugs to test and which thresholds to use as cut offs. Consistency in reporting should address not only positive results, but also what was tested, which cut offs were used, and whether tests were screens or confirmatory tests. The National Safety Council (NSC) Alcohol, Drugs and Impairment Division (ADID) has developed recommendations for standardized procedures. These should be promoted and adopted.
Impact on Data Systems
There is a great deal of interest in drugged driving data, but this information is difficult to obtain, according to the report. For example, if offenders test positive for alcohol, they are unlikely to be tested for drugs because of the time, expense, and difficulty in proving a drug-impaired driving case.
There is also very little “pre” data, so even when data is collected, it is difficult to interpret, since we do not know what conditions were present prior to the law change. When attempts are made to “compare” pre and post data, other variables can lead to misleading results. For example, if more attention is paid to drugged driving in a community, there may appear to be more positive drug results, but the increase may be because there is now more drug testing. In other words, there may have been as many positive results before, but we weren’t aware of it because there was less testing.
According to a participant on the expert panel, “The lack of data is tremendous.” And, “If it’s not measured, it can’t be addressed.”
As a result, states need to take into account a range of issues and seek expert advice before implementing a policy change in drug enforcement, according to the National Cooperative Research and Evaluation Program’s (NCREP) study.