How Common Is Drug Impaired Driving?

October 30, 2025 | By The Ye Law Firm Injury Lawyers
How Common Is Drug Impaired Driving?

Drug-impaired driving is a significant and dangerously common problem on our roads, though it is often harder to track with precise statistics than alcohol-impaired driving. Every year, millions of people get behind the wheel after using substances that compromise their ability to drive safely, leading to devastating and entirely preventable crashes on roads from Seattle to Tacoma and beyond. 

The choice of one person to drive while impaired can change another person’s life forever, creating a ripple effect of physical, emotional, and financial hardship.

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Key Takeaways about Drug Impaired Driving

  • National surveys indicate that millions of drivers operate vehicles under the influence of drugs like marijuana, prescription medications, and other illicit substances each year.
  • Unlike alcohol, there is no single, simple roadside test for the wide variety of drugs that can impair a driver, making enforcement and data collection more complex.
  • A wide range of substances can cause impairment, including illegal drugs, cannabis, and even legally prescribed or over-the-counter medications.
  • Drug-impaired driving can lead to slowed reaction times, poor judgment, and decreased coordination, all of which significantly increase the risk of a serious accident.
  • Victims of accidents caused by drug-impaired drivers have legal rights and may be able to seek compensation for their injuries and losses.

The Alarming Reality of Drug Impaired Driving in Washington

When you are driving along I-5 or navigating the busy streets of Bellevue, you trust that the drivers around you are alert, responsible, and sober. Unfortunately, that trust is broken far too often. While drunk driving gets a lot of attention, drug-impaired driving is a pervasive issue that contributes to thousands of injuries and deaths across the country.

According to the Centers for Disease Control and Prevention (CDC), self-reported surveys reveal a startling picture. In one recent year, an estimated 11.7 million people aged 16 or older drove under the influence of marijuana, while another 2.4 million drove under the influence of other illicit drugs. This doesn’t even account for the millions more who may be impaired by prescription or over-the-counter medications.

A major challenge in understanding the full scope of the problem is the difficulty in collecting data. There is no simple, universal roadside test for drugs like there is for alcohol. This means that drug-impaired driving is likely underreported in official crash statistics. 

However, organizations like the Washington Traffic Safety Commission (WTSC) work tirelessly to gather data and raise awareness, showing that drugged driving is a serious threat right here in the Pacific Northwest. According to the Commission’s data, alcohol is the most common substance detected among Washington drivers in fatal crashes, followed by Delta-9 THC. Drivers positive for two or more drugs or a combination of drugs and alcohol are the most common type of impaired driver in fatal crashes in the state. 

It’s Not Just Illegal Drugs: The Many Forms of Impairing Substances

A common misconception is that drug-impaired driving only involves illegal substances. In reality, any substance that affects your brain and body can make it unsafe to operate a vehicle. A driver can be held accountable for causing a crash regardless of whether the substance they used was legal or not.

Impairing drugs can include:

  • Prescription Medications: Many powerful medications prescribed by doctors come with clear warnings not to operate heavy machinery. This includes opioid painkillers, anti-anxiety drugs (like benzodiazepines), muscle relaxants, and some antidepressants. A driver who ignores these warnings and causes a crash can be considered negligent.
  • Cannabis (Marijuana): Since its legalization in Washington, there has been a significant focus on its effect on driving. THC, the active compound in cannabis, can slow reaction time, impair judgment of time and distance, and decrease coordination.
  • Over-the-Counter (OTC) Drugs: Even common remedies you can buy at any pharmacy can be dangerous for drivers. Antihistamines found in allergy medicine, sleep aids, and some cold and flu formulas can cause significant drowsiness, which can be just as dangerous as being intoxicated.
  • Illegal Stimulants and Narcotics: Drugs like cocaine, methamphetamines, and heroin have severe impacts on a driver’s cognitive function, perception, and behavior, often leading to aggressive and reckless driving that puts everyone on the road at risk.

Ultimately, the legality of a substance is not the main issue in a personal injury claim. The critical question is whether the drug impaired the driver’s ability to operate their vehicle safely, leading to the accident that caused your injuries.

How Drugs Affect a Person's Ability to Drive Safely

Different drugs impact the body in different ways, but nearly all of them interfere with the essential skills needed for safe driving. A moment of delayed reaction or a poor decision can have catastrophic consequences, especially during challenging driving conditions like the frequent rain and fog we experience in the Puget Sound region.

rear end car collision

Slowed Reaction Time

Driving requires constant, split-second reactions to changing conditions—a car stopping suddenly, a pedestrian stepping into a crosswalk, or a hazard on the road. Many substances, particularly marijuana and depressants like opioids, slow down the communication between the brain and the body. This delay can turn a potential near-miss into a devastating T-bone or rear-end collision.

Impaired Judgment and Decision-Making

Safe driving is a continuous series of judgments: how fast to go, when to change lanes, and how much space to leave between cars. Drugs can warp this process. Stimulants may make a driver overly aggressive and prone to speeding, while other substances can impair their ability to accurately judge distances, leading them to pull out in front of oncoming traffic or miscalculate a turn.

Decreased Coordination

Steering, braking, and accelerating all require fine motor skills and coordination. Drugs can disrupt this control, causing a driver to weave between lanes, overcorrect on a turn, or struggle to maintain a consistent speed. This lack of physical control makes them a hazard to everyone sharing the road.

Washington's Laws on Drug Impaired Driving

Washington State has very clear laws regarding driving under the influence of any substance. In Washington, it is illegal to drive a motor vehicle while under the influence of or affected by an intoxicating liquor, marijuana, or any drug.

For cannabis, Washington has established a "per se" limit. This means that any driver with a THC concentration of 5 nanograms or more per milliliter of blood is automatically considered to be driving under the influence. However, it is crucial to understand two things:

  1. A driver can still be found guilty of DUI even if their THC level is below 5 nanograms if there is evidence that the drug still affected their ability to drive safely.
  2. The outcome of the driver’s criminal case is separate from your civil personal injury claim. A person injured by an impaired driver can pursue compensation for their losses even if the at-fault driver is never criminally convicted. The purpose of a civil claim is to hold the negligent driver financially accountable for the harm they caused.

The Challenge of Proving Drug Impaired Driving in an Injury Claim

Because there isn’t a simple breathalyzer for most drugs, building a strong personal injury case against a drug-impaired driver requires a thorough and detailed investigation. An experienced personal injury attorney knows how to gather and use various forms of evidence to demonstrate that the other driver’s impairment caused the crash.

This evidence can include:

  • The Official Police Report: This report is a critical starting point. It will contain the investigating officer's observations about the driver's behavior, physical appearance (e.g., bloodshot eyes, slurred speech), and any statements the driver made at the scene.
  • Field Sobriety Test Results: While often associated with alcohol, officers may also conduct these tests for suspected drug impairment. The driver's performance can be powerful evidence of their condition.
  • Chemical Test Results: If the driver was arrested, they may have been required to submit to a blood or urine test. The results of these tests can definitively show the presence and concentration of drugs in their system.
  • Witness Testimony: Statements from other drivers, passengers, or pedestrians who saw the crash or the driver's erratic behavior before the collision can help paint a clear picture of what happened.
  • Expert Witness Analysis: In some cases, a toxicologist may be needed to explain to a judge or jury how a specific drug and concentration level would have impaired the at-fault driver's ability to operate a vehicle safely.

Gathering all this evidence and weaving it into a compelling narrative is key to holding the responsible driver accountable for their negligent actions.

Your Right to Fair Compensation

Being injured by an impaired driver is not just physically painful; it can also be a significant financial burden. A personal injury claim is a legal process that allows you to seek compensation, often called "damages," from the person whose negligence caused your harm. This isn't about punishment; it's about providing you with the financial resources you need to recover and move forward.

You may be entitled to compensation for a variety of losses, including:

  • All Medical Expenses: This covers everything from the initial emergency room visit and hospital stay to ongoing physical therapy, prescription medications, and any future medical care you may need.
  • Lost Income: If your injuries prevent you from working, you can seek compensation for the wages you have lost. If your ability to earn a living is permanently affected, you can also claim damages for your diminished future earning capacity.
  • Pain and Suffering: This is compensation for the non-economic impact of the crash, such as the physical pain, emotional distress, anxiety, and loss of enjoyment of life you have experienced.
  • Property Damage: This covers the cost of repairing or replacing your vehicle and any other personal property that was damaged in the accident.

No amount of money can undo the trauma of a serious accident, but securing fair compensation can relieve the financial stress and allow you to focus completely on your healing and recovery.

Drug Impaired Driving FAQs

Here are answers to some common questions that arise after an accident involving a potentially impaired driver.

Even if a medication is legally prescribed, a driver can still be held liable for an accident if the drug impaired their ability to drive safely. Most impairing medications come with warnings from the doctor and the pharmacy, and choosing to drive despite those warnings is a form of negligence.

Can I file a personal injury claim if the drug-impaired driver was not criminally charged or found guilty?

Yes, you can. The criminal justice system and the civil justice system are separate. A criminal case requires proof "beyond a reasonable doubt," a very high standard. A civil personal injury claim requires proof by a "preponderance of the evidence," which means showing it was more likely than not that the other driver’s negligence caused your injuries.

What is the time limit for filing a personal injury lawsuit in Washington?

In Washington State, the statute of limitations for most personal injury claims is three years from the date of the injury. If you do not file a lawsuit within this time frame, you will likely lose your right to seek compensation forever.

Why is it important to consult with an attorney quickly after a drug-impaired driving accident?

It is vital to act quickly to preserve crucial evidence. Witness memories fade, physical evidence from the scene can be lost, and strict legal deadlines must be met. A car accident attorney can immediately begin the investigation needed to build the strongest possible case on your behalf.

Justice You Deserve, Care You Can Trust

Chong Ye Attorney

Dealing with a serious car accident claim can be stressful. You may be in pain, out of work, and unsure of what to do next. At Ye Law Firm Injury Lawyers, founding attorney Chong Hae Ye understands the immense stress you are under, not just as a legal professional, but on a personal level.

Chong is deeply committed to ensuring no client ever feels unheard or unappreciated. He personally walks with each client through every step of the legal process, offering the kind, empathetic guidance you need during a difficult time. As a former pastor who is fluent in Korean and Spanish, he has a unique ability to connect with and support clients from all backgrounds, especially those who may find the American legal system intimidating.

If you or a loved one has been injured by a driver you suspect was impaired by drugs, let us help you seek the accountability and financial recovery you deserve. Contact Ye Law Firm Injury Lawyers today at (253) 946-0577 or through our online form for a free, no-obligation consultation. We work on a contingency fee basis, which means you pay no upfront costs and we only collect a fee if we successfully recover compensation for you.