In Oklahoma, marijuana is illegal for recreational use. However, its usage for medicinal purposes was legalized in 2018.

When considering the number of people who use it illegally for recreational purposes and legally for medicinal purposes, around 47.2% of Oklahoma residents over the age of 18—or more than 1.4 million people—are estimated to have used the drug in 2022, according to a report by Cannabis Public Policy Consulting.

That means when you’re on the road, there’s a good chance you’ll encounter drivers who are under the influence of this drug. If you’re involved in a crash where marijuana was a factor, it’s important to know how it may have contributed to the crash and whether its use can play a role in establishing liability for crash victims.

How Does Marijuana Affect a User’s Driving Ability?

Despite being legal for medicinal purposes in Oklahoma, it’s still illegal to drive under the influence of marijuana in the Sooner State, the same way it’s illegal to drive under the influence of alcohol with a blood alcohol content (BAC) of 0.08% or higher.

That’s because the psychoactive compound in marijuana called tetrahydrocannabinol (THC) negatively affects many skills that are required for safe driving. This can result in:

• Altered Perception and Sensory Skills: Marijuana can alter the user’s sense of time and space. This alteration can lead to misjudging speeds and distances, which are critical skills for safe driving.

• Impaired Coordination: THC affects motor coordination and reaction times. Drivers under the influence of marijuana may have slower reaction times to unexpected events, such as another driver suddenly breaking or a pedestrian stepping out into the road, making it harder to respond quickly to avoid accidents.

• Reduced Concentration and Attention: Marijuana use can lead to difficulties in maintaining attention and concentration, which are essential for safe driving. Users might find it hard to focus on the multiple tasks required for driving, such as watching for pedestrians, monitoring traffic signals, and observing other vehicles.

• Impaired Judgment and Decision Making: THC can impair the user’s judgment. This impairment can lead to poor decision-making on the road, like misjudging the need to stop or yield, or making risky maneuvers.

• Drowsiness: Some strains of marijuana, especially those high in another compound called CBD (cannabidiol), can cause drowsiness or lethargy, which can be particularly dangerous when driving.

• Increased Anxiety or Paranoia: In some people, marijuana can induce anxiety or paranoia, which can distract the driver and impair their ability to operate the vehicle safely.

How Can You Prove a Driver Was Impaired by Marijuana During a Crash?

Proving that someone was under the influence of marijuana after a crash presents several challenges, primarily due to the nature of how marijuana is metabolized and detected in the body, as well as legal and scientific limitations.

Here are some of the key challenges:

• Lack of Reliable Roadside Testing: Unlike alcohol, for which there are effective and immediate roadside tests like breathalyzers, there is no universally accepted, quick test for marijuana impairment.
• THC Detection in Blood Tests: Blood tests can detect THC, but there are significant limitations. Small amounts of THC can remain in the bloodstream for days or weeks after use, especially in regular users, making it difficult to ascertain if the individual was impaired at the time of the accident.
• No Consensus on Impairment Levels: There is no universally accepted standard for how much THC in the blood constitutes impairment. Unlike alcohol, where a BAC of 0.08% is widely accepted as the threshold for significant impairment, no such consensus exists for THC levels.
• Variability in Individual Tolerance: People have different tolerances to THC, and regular users may show high levels of THC in their system but may not be functionally impaired, while occasional users might be significantly impaired with lower levels.
• Delayed Testing: The time between the accident and when a blood test is administered can be crucial. THC levels decline rapidly in the bloodstream, so delays in testing can affect the results and their interpretation.
• Legal and Privacy Concerns: Obtaining a blood test for THC can require a warrant. This requirement, along with privacy concerns and potential legal challenges, can complicate the process of using such tests in a legal case.
• Influence of Other Substances: If other substances, such as alcohol or prescription drugs, are also present in the system, it can be challenging to isolate the specific impact of marijuana on the driver’s impairment.

Due to these challenges, car accident cases involving marijuana usage and impairment often require a multifaceted approach, including the use of expert witnesses, detailed accident reconstruction, and a thorough examination of all the available evidence to establish whether drivers were impaired by the drug when their crashes occurred.

Marijuana Usage Can Decrease Compensation for Crash Victims in Some Cases

Oklahoma is a comparative negligence state. When a driver is 50% or more at fault for a crash, they can’t pursue compensation for their damages. However, drivers who are 49% or less at fault can pursue compensation, but the amount of money they can receive is reduced by their percentage of liability.

In some cases, marijuana impairment can cause a driver to lose a significant percentage of their compensation if it’s ruled to have contributed to the crash they were injured in.

For example, a distracted driver may crash into a vehicle driven by a person who is impaired by marijuana. Although the distracted driver ultimately caused the crash, it could be ruled that the impaired driver would have been able to make an evasive maneuver to avoid the collision if their reaction times weren’t reduced by marijuana. In this case, the distracted driver would face the majority of the blame, while the impaired driver may face a smaller percentage of fault that reduces their compensation.

Contact Our Oklahoma Car Accident Lawyers After a Marijuana-Related Crash

Despite it being illegal to drive under the influence of marijuana in Oklahoma, including legally obtained medicinal marijuana, countless people do it every day in our state. The effects marijuana has on driving ability are real and dangerous, and the number of crashes it causes may never be known due to how difficult it is to accurately test for it in the aftermath of a collision.

Despite those difficulties, our Oklahoma City car accident attorneys have helped many people involved in crashes where marijuana usage was a factor, and we can help you, too. Contact us today for a free case review. We’ll use our decades of experience and vast collection of resources to help you get the compensation you deserve.