Recreational marijuana is highly accessible in Colorado. Those over the age of 21 may legally purchase it at a dispensary, and those under 21 often have easy access through friends, fake ID's, and the black market. Easy access to marijuana has also resulted in increased training for law enforcement to recognize, arrest and charge those found to be driving high.
Most young adults who consume alcohol understand - or can quickly find out - what a BAC above the "legal limit" of 0.08 means in terms of beer, wine, and liquor. Apps and websites give a rough estimate of a BAC based on weight, drinks, and time, and portable breath tests are available for purchase.
But what does it mean to be "too high" to drive after consuming marijuana? While there is no quick and easy answer, there are a few things that you must know.
First, if a police officer has probable cause to believe your ability to drive is impaired due to marijuana or other drugs, they may demand that you submit to a blood test. Refusing to submit to such a test results in a 1-year suspension of your license and can be used as evidence against you at trial. People who have used marijuana often mistake this blood test with a "drug test" that simply shows past use.
While most test results will include inactive metabolites that show past use, what matters for criminal charges is the presence of Delta-9-THC. Delta-9-THC is what makes a person feel "high" and, unlike inactive metabolites that can stay in your system for weeks or even months, Delta-9-THC levels will typically drop below the "presumptive limit" within a few hours of use as the effects of marijuana wear off. In short, if you no longer feel high, you may pass a blood test even if the test does show the that there is marijuana in your system.
Second, even if a blood test result is above Colorado's "presumptive limit" for Delta-9-THC blood concentration, scientific studies by unbiased organizations such as the National Highway Traffic Safety Administration have shown that, unlike alcohol, it is very difficult to correlate a blood test level of marijuana to a level of impairment without considering all other factors. Regular marijuana users are at risk of a high blood test result despite perfect driving and no signs of impairment.
If you are charged with driving under the influence of marijuana, the prosecutor must prove impairment, not just that you had a blood test with a result above a specific number. While a low result may protect you from prosecution, a high result does not mean you will be convicted at trial unless there is proof that you were actually impaired.
Third, a major factor in a law enforcement officer's decision to require a blood test is performance on field sobriety tests. Officers are taught to recognize signs of impairment that are drug-specific and are trained on roadside maneuvers designed to detect drug-based impairment. Officers look for things such as eyelid flutters, how quickly a person estimates the passage of 30 seconds with their eyes closed while counting in their head, and whether a person can cross their eyes while focusing on a stimulus. Such tests are voluntary. Not only to do you have the right to refuse such tests, you also have the right to prevent the prosecution from arguing that refusing to perform a voluntary test shows that you are more likely to be guilty.
Many traffic stops escalate into impaired driving investigations when police officers see drug paraphernalia or can smell the odor of fresh or burnt marijuana in a vehicle. It is important to remember that even if you are over 21 and have waited for the effects of marijuana to completely subside before driving, any marijuana or paraphernalia should be stored in a closed container out of reach of the front seats of a vehicle, and it never advisable to drive a vehicle that smells like marijuana, even when completely sober.
Finally, those under the age of 21 face the possibility of additional charges if there are found to be in possession of marijuana or marijuana paraphernalia.
If you are facing a charge for driving under the influence of marijuana, it is important to retain a lawyer experience in defending such charges and who understands both the laws and the scientific research regarding marijuana and impaired driving.