Driving high, driving distracted, or driving drunk: why none of it mixes with safety 

April is Distracted Driving Awareness Month, a reminder that safe driving depends on one simple thing: attention. Anything that pulls your eyes, hands, or mind away from the road increases crash risk—including phones, fatigue, alcohol, or marijuana. With 4/20 also falling this month, it’s a good time to clear up a few persistent myths about cannabis, alcohol, and driving. 

Since Washington and Oregon legalized recreational marijuana (in 2012 and 2015, respectively), traffic-safety researchers have worked to better understand how marijuana affects drivers—especially when it’s combined with alcohol. Questions still come up: Is driving high safer than driving drunk? What happens when people use both? Can they cancel each other out? 

The short answer: no, no, and no. 
 

Alcohol, marijuana, and the danger of divided attention 

Research consistently shows that both alcohol and marijuana impair driving, just in different ways—and using them together is worse than either alone.  

• Alcohol tends to reduce judgment and self-control. Drivers are more likely to speed, overestimate their ability, and take risks. 
• Marijuana is more often associated with slower reaction time, difficulty staying centered in a lane, and trouble responding quickly when something unexpected happens—like another driver making a mistake. 
• Using both substances amplifies impairment, further degrading attention, coordination, and lane control.  

From a prevention perspective, what matters most is this: impaired driving is a form of distracted driving. Whether your attention is pulled by a phone, a substance, or a mix of both, the outcome is the same—less time and ability to respond safely. 

Why marijuana impairment is harder to measure—but no less real 

Unlike alcohol, there’s no widely accepted roadside test that correlates marijuana levels with impairment in the way a breathalyzer does with alcohol. THC can remain detectable in the body long after the “high” has worn off, and impairment varies based on factors like tolerance and method of use.  

That scientific uncertainty doesn’t mean marijuana is “safe” for driving. Studies show it can impair reaction time, attention, and the ability to multitask—skills every driver needs. And when marijuana is combined with alcohol, impairment increases significantly.  

Alcohol: clearer data, same conclusion 

Where alcohol is concerned, the data is well established. A blood alcohol concentration (BAC) of 0.08% increases crash risk by about four times compared to a sober driver, and impairment begins at much lower levels.  

Because alcohol testing is straightforward and legally definitive, law enforcement often doesn’t test for drugs once a driver exceeds the legal alcohol limit. Safety experts note this can lead to an undercount of drivers impaired by multiple substances, even though research indicates combined use is common.  

Has legalization changed crash patterns in the Pacific Northwest? 

Studies from the Insurance Institute for Highway Safety found that police-reported crash rates increased in states that legalized recreational marijuana, including Washington and Oregon, compared with neighboring states.  

Research from the Washington Traffic Safety Commission also shows a growing share of fatal crashes involving polydrug use—drivers testing positive for both alcohol and marijuana—highlighting the added risk when substances are combined.  

These findings underscore an important prevention message: the issue isn’t legality—it’s impairment. 

Consequences extend beyond the crash 

Impaired driving can carry severe legal and financial consequences, ranging from fines and license suspension to jail time depending on the circumstances and state law. A DUI conviction can also significantly increase insurance costs and limit coverage options, reflecting the heightened risk impaired driving poses to everyone on the road. 

But the most serious consequences can’t be measured in dollars or penalties. Lives are changed—or lost—when attention behind the wheel slips. 

Prevention starts before the keys ever turn 

Whether you’re celebrating, hosting, or just running errands this April, these prevention-first steps help reduce risk for everyone: 

• Plan ahead. If cannabis, alcohol, or other impairing substances are part of the plan, arrange a sober ride, rideshare, or overnight stay. 
• Don’t mix substances and driving—at all. Even small amounts can affect attention and reaction time. 
• Remove temptation. Set navigation and music before you start driving and keep phones out of reach. 
• Speak up. If a driver seems impaired or distracted, say something—or find a safer ride. 
• Model safe behavior for teens. A no-questions-asked ride home is one of the strongest prevention tools parents can offer. 

If you encounter a driver who appears impaired, report it. In Washington, call 9‑1‑1; in Oregon, dial *677 or 9‑1‑1. 
 

Staying focused helps everyone get home 

At PEMCO, prevention is about reducing risk before something goes wrong. During Distracted Driving Awareness Month—and every month—staying focused, sober, and attentive behind the wheel is one of the simplest ways we can look out for one another. 

Note: While we’re experts in loss prevention and road safety, this article is for educational purposes only and not legal advice. For legal guidance, please consult local authorities or an attorney.