Since Colorado legalized marijuana for recreational use in 2014, the state has become a focal point for discussions on marijuana legalization and its impact on public safety. While marijuana use is legal for adults 21 and older, driving under the influence of marijuana remains a serious offense. In Colorado, DUI laws apply not only to alcohol but also to marijuana. However, the intersection of marijuana use and DUI laws raises important questions regarding legal thresholds, impaired driving, and how the law affects individuals who use marijuana.
As a driver in Colorado, it’s important to understand how marijuana affects your ability to drive and what the law says about driving while under its influence. This article examines the legal landscape of marijuana and DUI in Colorado, how marijuana use affects DUI cases, and what defenses are available if you’re charged with a marijuana-related DUI.
What Does Legalization Mean for Marijuana and Driving? 
Marijuana is fully legal for recreational use in Colorado, but that doesn’t mean you can freely drive after using it. Similar to alcohol, marijuana use impairs your ability to drive safely. Despite marijuana being legal, Colorado law does not permit anyone to drive while under the influence of marijuana.
Colorado law recognizes that marijuana can impair judgment, motor skills, and reaction time, all of which are necessary for safe driving. Just like alcohol, marijuana use can create unsafe driving conditions. This is why law enforcement officers can charge a driver with DUI if their impairment is caused by marijuana.
The Legal THC Limit in Colorado DUI Cases
In Colorado, marijuana DUI laws are based on the presence of THC in a person’s bloodstream. THC is the active chemical in marijuana that causes impairment. The legal limit for THC in a person’s blood is set at 5 nanograms per milliliter (ng/mL). If a driver’s blood THC concentration exceeds this threshold, they can face DUI charges, just like a driver with a blood alcohol concentration (BAC) of 0.08% or higher.
However, the situation becomes complicated because marijuana affects people differently than alcohol. While the blood alcohol concentration correlates directly to impairment in most cases, the level of THC in a person’s blood does not always directly reflect the level of impairment. THC can stay in the body for days after use, making it difficult to determine if a person is truly impaired while driving. This has led to challenges in defining impairment based solely on THC levels.
Field Sobriety Tests and Marijuana DUI Charges
If you’re pulled over by law enforcement officers, you may be asked to perform field sobriety tests. While these tests are commonly used for alcohol-related DUI cases, they are also a part of marijuana DUI investigations. However, field sobriety tests are not perfect indicators of marijuana impairment, as they are typically designed to detect alcohol impairment, not marijuana.
Marijuana can impair motor coordination, but it also affects cognitive functions such as memory, attention, and decision-making. For this reason, some individuals might pass traditional field sobriety tests even if they are under the influence of marijuana. Officers may use additional signs of impairment, such as bloodshot eyes, erratic driving behavior, or the smell of marijuana, to build a case against the driver.
If a driver is suspected of being impaired by marijuana, the officer may request a blood test to determine the THC level in their system. If the driver’s THC levels are above the legal limit, they may be arrested and charged with DUI.
What if I Have a Medical Marijuana Card?
Colorado is home to a large number of medical marijuana users who are legally permitted to use marijuana for various health conditions. While having a medical marijuana card does provide legal protections in certain areas, it does not provide immunity from DUI laws. Medical marijuana users are still subject to the same DUI laws as recreational users.
If a medical marijuana patient is pulled over and suspected of being impaired, they can still be arrested and charged with a marijuana DUI if their THC levels exceed the legal limit. Having a medical marijuana card may be considered during the legal process, but it does not excuse driving while impaired.
Defenses Against a Marijuana DUI Charge in Colorado
Being arrested and charged with a marijuana DUI can have serious consequences, including fines, license suspension, and even jail time. However, there are potential defenses that can be raised in marijuana DUI cases.
- Challenging the THC Blood Test Results
One common defense is to challenge the validity of the blood test results. THC can remain in a person’s system long after the effects have worn off. A blood test may show high levels of THC, but the person may not be impaired at the time of driving. A skilled attorney can work with experts to challenge the interpretation of blood test results and argue that the driver was not impaired at the time of the arrest.
- Questioning the Officer’s Observations
Field sobriety tests and an officer’s observations may not always provide an accurate representation of impairment. For instance, a driver’s failure to perform well on field sobriety tests may be due to other factors, such as medical conditions or nervousness, rather than marijuana impairment. If there is a lack of evidence to show that a driver’s impairment was caused by marijuana use, it could weaken the prosecution’s case.
- Lack of Proper Procedure or Legal Violations
Another defense may involve a violation of the driver’s constitutional rights. For example, if the officer did not have reasonable suspicion to stop the vehicle or did not follow proper procedures during the investigation, the defense may argue that the evidence gathered should be suppressed.
The Role of Expert Testimony in Marijuana DUI Cases
Given the complexity of marijuana impairment, expert testimony is often crucial in DUI cases involving marijuana. An expert in drug impairment or toxicology can testify about the effects of marijuana on driving ability and how THC levels in the blood may not necessarily correlate with a driver’s impairment at the time of the offense.
An expert might also explain the differences between marijuana and alcohol impairment, helping the court understand why a person with elevated THC levels might not have been impaired or unfit to drive.
The Importance of Legal Representation
If you are facing marijuana DUI charges in Colorado, it’s important to have experienced legal representation. A skilled DUI defense attorney can assess your case, challenge the evidence, and work to minimize the impact of the charges. The complexities of marijuana DUI cases require a defense lawyer who understands both the science and the law related to marijuana impairment.
Hebets & McCallin P.C. is dedicated to helping clients navigate DUI charges related to marijuana use. If you’ve been arrested for a marijuana-related DUI, contact us for a free consultation to discuss your options.
While marijuana is legal in Colorado, driving under the influence of marijuana is still a serious crime. The state’s DUI laws are clear: if you are caught driving while impaired by marijuana, you can face serious penalties, even if your THC levels are within the legal limit. Understanding how marijuana affects driving ability, the legal limits for THC, and the potential defenses available in DUI cases can help you make informed decisions if you find yourself facing DUI charges related to marijuana use.
Always remember, driving safely is not just a legal obligation, but a responsibility to protect yourself and others on the road.
Hebets & McCallin P.C. focusing on defending DUI cases, including marijuana-related offenses. Contact us today to discuss how we can help you with your case.