When Michigan legalized recreational marijuana in 2018, it changed certain aspects of state law, including how car accident cases are handled. While recreational cannabis use is now legal for adults, driving under its influence remains strictly prohibited. The problem is that proving impairment, determining fault, and securing fair compensation in a marijuana-related accident isn’t always straightforward.
Unlike alcohol, which has a clearly defined legal limit, marijuana affects drivers differently and lingers in the body long after its effects wear off. This creates serious challenges in accident investigations, criminal prosecutions, and insurance settlements. What happens when a driver tests positive for THC but claims they weren’t impaired? How do insurers handle claims when fault is disputed? And how can victims of impaired driving accidents fight for the compensation they deserve?
This guide outlines how Michigan’s marijuana laws impact car accident settlements, what legal hurdles victims may face, and how an experienced personal injury attorney can help with these complicated cases.
What is Michigan’s Recreational Marijuana Law?
In 2018, Michigan voters approved the Regulation and Taxation of Marijuana Act (MRTMA), making it legal for adults 21 and older to possess, consume, and grow marijuana for personal use. However, this law does not grant immunity to those who drive under the influence.
Key provisions of Michigan’s marijuana law include:
- Legal Possession: Adults can legally possess up to 2.5 ounces of marijuana outside their home and up to 10 ounces inside their home.
- Driving Restrictions: Operating a vehicle under the influence of any controlled substance, including marijuana, remains illegal.
- Employer Rights: Businesses can still prohibit employees from using marijuana, and law enforcement can arrest drivers suspected of impairment.
Marijuana-Impaired Driving and Michigan’s Legal Standards
Under Michigan law (MCL 257.625), driving while impaired by alcohol, drugs, or a combination of both is illegal. However, proving marijuana impairment is far more complicated than proving alcohol impairment. While blood alcohol concentration (BAC) has a clear legal limit of 0.08%, marijuana does not have a universally accepted threshold for intoxication.
Without a defined legal THC limit, prosecutors, law enforcement officers, and insurance companies must rely on other forms of evidence to determine whether a driver was impaired. This lack of clarity can impact motor vehicle accident settlements, making it easier for insurers to dispute liability and more difficult for injured victims to secure fair compensation.
Zero-Tolerance vs. Impairment-Based Laws
Michigan’s approach to marijuana-impaired driving laws has evolved over the years. The state once had a zero-tolerance policy, meaning that any amount of THC in a driver’s system was enough for a conviction. However, this policy was challenged in court because marijuana can stay in the body for weeks, even after its effects have worn off.
In People v. Koon (2013), the Michigan Supreme Court ruled that registered medical marijuana users could not be convicted of DUI solely based on THC presence. This case forced Michigan to abandon its zero-tolerance approach and replace it with an impairment-based system where prosecutors must now prove actual impairment, not just the presence of THC.
This shift means that drivers who test positive for marijuana are not automatically considered impaired. Instead, law enforcement must present additional evidence of impairment, creating challenges for prosecutors in criminal cases and complicating civil liability in auto accident claims.
How Police Determine Marijuana Impairment
To determine whether someone is under the influence of marijuana, law enforcement officers rely on a combination of field sobriety tests, officer observations, and chemical testing to determine whether a driver was too impaired to operate a vehicle safely.
Field Sobriety Tests
When an officer suspects a driver of marijuana impairment, they may conduct standardized field sobriety tests (FSTs), which include:
- The Horizontal Gaze Nystagmus (Hgn) Test: Officers check for involuntary eye movements that could indicate intoxication.
- The Walk-And-Turn Test: Drivers must walk in a straight line, turn, and return without losing balance.
- The One-Leg Stand Test: Officers observe a driver’s ability to balance on one foot.
While these tests are widely used, they were originally intended to detect those driving under the influence of alcohol. Marijuana affects coordination and reaction time differently, making these tests less reliable for determining THC-related impairment.
Officer Observations
Since chemical tests alone cannot prove marijuana impairment, officers rely heavily on their own observations. When pulling over a suspected impaired driver, police look for signs such as:
- Erratic driving patterns, such as swerving or delayed reactions
- Bloodshot or glassy eyes
- Slurred speech or confusion
- The smell of marijuana in the vehicle
- Delayed responses to commands
However, these signs are not exclusive to being under the influence of marijuana. Fatigue, medical conditions, and even stress can mimic the symptoms of intoxication. This reliance on subjective observations makes marijuana-related DUI cases harder to prove and creates more room for dispute in accident settlements.
Blood Tests and THC Levels
If an officer believes a driver is impaired by marijuana, they may request a blood test to measure THC concentration. However, even this method is not foolproof.
THC levels in the blood do not correlate directly with impairment. Unlike alcohol, which has a predictable absorption and elimination rate, THC affects individuals differently depending on tolerance, metabolism, and frequency of use. A regular marijuana user may have detectable THC levels days or even weeks after last consuming cannabis, while a first-time user may have low THC levels but still be impaired.
No Agreed-Upon THC Limit for Impairment
Several states have attempted to establish legal THC limits for impaired driving and some have set a threshold between 2 to 5 nanograms per milliliter (ng/mL) of blood. For example:
- Colorado: 5 ng/mL (permissible inference law)
- Montana: 5 ng/mL (per se limit)
- Nevada: 2 ng/mL (per se limit)
- Ohio: 2 ng/mL (per se limit)
- Pennsylvania: 1 ng/mL (zero-tolerance per se limit)
- Washington: 5 ng/mL (per se limit)
- Illinois: 5 ng/mL (per se limit)
However, Michigan has not adopted a per se THC limit, largely because science has not established a reliable threshold that indicates impairment for all users. Since there is no standard “legal limit” for marijuana, drivers can test positive for THC but still argue that they were not impaired at the time of the accident. This uncertainty creates challenges in both criminal prosecutions and civil accident claims, making it easier for insurance companies to deny liability or reduce settlements.
How a Michigan Car Accident Lawyer Can Help if You’re Injured by a Cannabis-Impaired Driver
Being injured in a marijuana-related car accident can leave you with medical expenses, lost wages, and ongoing pain. Since Michigan law does not set a clear legal THC limit for drivers, holding an impaired driver accountable can be challenging, but a Michigan car accident lawyer can use their experience and resources to fight for the best results in your case.
Proving the At-Fault Driver Was Impaired
Since Michigan law requires proof of impairment rather than just the presence of THC, an experienced car accident lawyer will work to establish that the driver’s marijuana use directly contributed to the crash. This often involves gathering critical evidence such as:
- Police Reports: Officers include details on suspected impairment in their accident reports, including observations of erratic driving, delayed reactions, or signs of intoxication.
- Field Sobriety Tests: If the driver failed field sobriety tests, this can be used to show their impaired judgment and motor skills.
- Toxicology Reports: A personal injury lawyer will review blood test results to determine how much THC was in the driver’s system and whether other substances (such as alcohol) were also present.
- Eyewitness Statements: Passengers, bystanders, or other drivers may have seen the at-fault driver smoking marijuana before driving or displaying signs of impairment.
- Traffic Camera or Dashcam Footage: Video evidence showing reckless or impaired driving behavior can be critical in proving fault.
- Expert Testimony: Toxicologists and accident reconstruction specialists may be called to explain how THC levels impact driving ability and demonstrate how the at-fault driver’s impairment caused the crash.
Holding the At-Fault Driver Financially Responsible
After proving impairment, your car accident attorney will work to ensure you receive full compensation for your losses. Since Michigan follows a comparative negligence system, the insurance company may try to argue that you were partially responsible for the motor vehicle accident to reduce your payout. A lawyer will fight back against these tactics by demonstrating that:
- The other driver’s impairment directly caused the accident
- You followed traffic laws and were not at fault
- Your injuries were directly caused by the crash
Once liability is established, your auto accident attorney will calculate the full extent of your damages and negotiate with the insurance company to secure maximum compensation.
Securing Compensation Through Insurance Claims
Since Michigan is a no-fault state, injured drivers typically turn to their Personal Injury Protection (PIP) coverage to cover medical expenses and lost wages. However, if your injuries are severe or the other driver was grossly negligent, you may be able to file a third-party lawsuit against the impaired driver for additional damages.
Filing a PIP Claim
Even if the impaired driver was at fault, your own insurance policy provides immediate coverage for medical bills and lost wages under Michigan’s no-fault system. However, insurance companies frequently underpay or delay valid claims. An attorney will:
- Make sure your personal injury claim is filed correctly and on time
- Push back against any unjust claim denials or delays
- Negotiate with your insurance provider to get the full amount owed
Pursuing a Third-Party Lawsuit
When you suffer severe injuries (such as broken bones, traumatic brain injuries, spinal cord damage, or permanent disability), you may qualify to file a third-party lawsuit against the impaired driver. An experienced car accident lawyer will work to recover damages that go beyond what PIP covers, including:
- Pain and suffering
- Future lost wages if you are unable to work
- Long-term rehabilitation or medical care costs
Fighting Back Against Insurance Company Tactics
Insurance companies often try to reduce or deny payouts in marijuana-related crashes. Since Michigan law does not define a THC impairment limit, insurers may argue that:
- The driver wasn’t actually under the influence of marijuana despite testing positive for THC
- The accident was not caused by marijuana use but by other factors
- You were partially at fault, so your settlement should be reduced
An attorney will build a strong case backed by evidence to counter these tactics. If the insurance company refuses to offer a fair settlement, your personal injury lawyer can take the case to court to fight for the compensation you need.
What If the Impaired Driver Was Uninsured?
If the at-fault driver does not have insurance or only carries the minimum required coverage, you may be able to recover compensation through your own uninsured/underinsured motorist (UM/UIM) policy. However, insurance companies often try to minimize payouts on UM/UIM claims, just as they do with regular accident claims.
A car accident lawyer will:
- Review your insurance policy to determine your coverage options
- Negotiate with your insurer to maximize your compensation
- Take legal action if your insurer refuses to honor your policy
Filing a Wrongful Death Lawsuit for Fatal Marijuana-Related Crashes
If a loved one was killed in an accident involving a driver under the influence of cannabis, you may have grounds for a wrongful death lawsuit. Michigan law allows surviving family members to seek compensation for:
- Funeral and burial expenses
- Loss of companionship and emotional suffering
- Loss of financial support
- Medical bills related to the accident before death
A wrongful death attorney can investigate the fatal crash, prove the impaired driver’s fault, and fight for justice on behalf of your loved one.
Get a Free Consultation After a Marijuana-Related Crash
Michigan’s marijuana laws complicate car accident settlements by making it harder for victims to get fair treatment. Since THC can remain in the bloodstream long after use, proving impairment is difficult, and insurance companies use this uncertainty to reduce or deny settlements.
If you were injured in an accident involving a marijuana-impaired driver or if your claim has been unfairly denied, you need an experienced attorney to fight for the compensation you need. The Lee Steinberg Law Firm has years of experience handling marijuana-related car accident cases and knows how to challenge unfair insurance tactics. Call us today at 1-800-LEE-FREE for a free consultation, or fill out our online contact form and let us help you secure the settlement you’re entitled to.