Colorado laws pertaining to the medicinal and recreational use of marijuana have changed drastically over the past several years, and other laws have had to adapt in response. Driving under the influence of prescription drugs has long been covered by DUI laws, and the law now sets parameters for marijuana. Similar to measuring a driver’s blood-alcohol content, drivers can be charged with a DUI if they are found to have 5 nanograms of tetrahydrocannabinol (THC) in 1 milliliter of blood.

The law is clear on what it means to drive under the influence of marijuana, but does the science back it up? Blood-alcohol content is a reliable predictor of alcohol intoxication. The same is simply not true for marijuana. Impairment from marijuana does not instantly occur when the THC enters the blood, but instead when it enters the brain’s fatty tissues. THC levels can even spike in the blood stream before any effect begins.

A study trying to determine a better way to pinpoint marijuana intoxication involved examining typical field sobriety tests administered during traffic stops prior to taking blood samples. Of those who failed the field sobriety tests and were later accused of being under the influence of alcohol, approximately 70 percent did not have the 5 nanograms of THC per milliliter. One expert claims that marijuana is simply not the same as alcohol, and approaches used to predict alcohol intoxication are not sufficient for the newly legalized drug.

Concern regarding marijuana intoxication behind the wheel has risen among Colorado law enforcement over recent years. Driving under the influence is an understandable issue to be worried about, but with no reliable predictor of intoxication, some drivers might be facing unwarranted charges. When faced with criminal allegations such as a DUI, defendants are often well advised to begin creating strategic defense plans in as timely a manner as possible.

Source: livescience.com, “Does Driving High on Marijuana Increase Fatal Crashes?“, Tia Ghose, May 10, 2016