In Best Known “Pot” State, Most Impaired Driving Still Linked to Alcohol

When Colorado became the first U.S. state to permit the sale of recreational marijuana in 2014, some expressed concerns that the state would see a huge spike in drug-impaired driving. Four years later, the Colorado Division of Criminal Justice reports that cannabis alone accounts for about 6% of DUIs, while more than 90% of impaired drivers are under the influence alcohol or a combination of drugs and alcohol.

The division’s July 2018 report, “Driving Under the Influence of Drugs and Alcohol, A Report Pursuant to House Bill 17-1315,” looks at Colorado’s 2016 DUI data—the most recent numbers available—to determine rates of alcohol- and drug-impaired driving. During that year the state reported 27,244 case filings with at least one DUI charge.

Drugged driving has become a pressing issue for many communities in recent years due to the rapid legalization of cannabis and the opioid crisis. While those concerns are well founded, the Colorado study highlights that drunk driving is still a significant danger on U.S. roadways.

Findings on Drugged and Drunk Driving

The report found key similarities between drugged and drunk driving and some important instances where they differ. Among the results:

• Speeding charges were more likely to be associated when the suspect was only under the influence of alcohol compared to only under the influence of THC.
• Nearly 38% of defendants stopped in 2016 had prior DUI convictions.
• Almost three-quarters of DUI defendants were male, regardless of substance.
• Alcohol and THC both metabolize quickly, and the data shows both BAC results and THC readings were higher the sooner a test was completed after a stop.
• Contrary to common expectations, Colorado law enforcement obtained blood tests more quickly than breath tests. The median time between a traffic stop and breath test was 76 minutes, compared to 64 minutes for a blood draw.

More Data Needed On Driving While High

One key finding related to drugged-driving: the picture is very incomplete.

As of June 2018, 31 states and Washington D.C. allow medicinal marijuana use and nine states plus the District of Columbia allow recreational use. Even as more states legalize marijuana, law enforcement continues to face challenges with detecting and recording drugged driving.

Police and sheriff’s departments have used alcohol breath testers for decades. However, there is no reliable roadside chemical test to determine if a person is driving under the influence of cannabis. Officers may need to call in a Drug Recognition Expert (DRE) to conduct a field sobriety test. In addition, an evidentiary test for drugs—often the most credited piece of evidence in a DUI case—requires a blood sample.

As many drugged driving suspects also have alcohol in their systems, jurisdictions often don’t test for drugs if the person has already failed an alcohol breath test. Drug tests can cost jurisdictions anywhere from $100 to $500 each, and “the additional time and cost required for further toxicology testing may not be considered worthwhile if the burden of proof for impairment is already being met by a BAC level.”

Finally, court systems don’t have a consistent way to record drug data for DUI cases. This combination of factors means that drug-impaired driving is likely unrepresented in the available data.

The Fight Against Impaired Driving

The study’s results don’t suggest that officials should be unconcerned about high drivers. Many jurisdictions report that while drunk driving still outpaces drugged driving, the rate of drivers under the influence of marijuana and opioids is clearly on the rise.

Drivers under the influence of alcohol are more likely to make other dangerous driving choices, including adding drugs to the mix, speeding, or driving distracted. And the study notes, “combining marijuana and alcohol increases impairment and motor vehicle crash risk more than each alone.” Ultimately, the data suggests that successful education and enforcement efforts need to focus on impaired driving as a whole. Drugged and drunk driving are closely linked and pose a serious danger on the roads.