Marijuana Legalization Creates Problems On The Roads

With legalized recreational marijuana, states grapple with ways to deal with toking and driving

Herbal enthusiasts in Colorado and Washington scored major victories last November when voters passed measures to allow the recreational use of marijuana.

As revelers toked up in celebration and Frito Lay stockholders prepared for their incoming windfall, state lawmakers were faced a number of issues regarding its regulation. One of the foremost questions: How to deal with people who smoke and drive.

Like alcohol and other drugs, marijuana inhibits a person's ability to operate a vehicle. Because of this, lawmakers needed legislation that would define how much pot is too much to drive, and then what penalties awaited those who exceed the limit.

The two states decided to handle the situation in different ways, as Edmunds laid out in a recent post. So if you plan on partaking in some non-medical Mary Jane is either Washington or Colorado, here's what you need to know:


Edmunds explains that Washington has a set legal limit of THC -- marijuana's active ingredient -- that a driver can have in their blood before they are classified as driving under the influence. That level is 5 nanograms of THC per milliliter of blood. If a driver is above that level, which can be determined by taking a blood sample, then the case is treated like any other DUI infraction.

For a first offense, even before conviction, drivers face a 90-day license suspension and various hefty fines, which depend on the court. If a conviction occurs, offenders could then be subject to a four-year license suspension, drug rehab classes and many, many more fines and fees.


In Colorado, there is no set legal limit for THC in the blood for drivers. How to handle people driving after smoking pot is an ongoing debate.

Interestingly, in one of the newer legislation drafts, lawmakers "are recommending that drivers who test over the legal THC limit could argue they were not impaired," according to Edmunds.

This proposed law would make it so a DUI conviction had to be based on driving impairment, not just the amount in one's system. Colorado legislators are expected to take a serious look at the proposal some time this year.

Arguments against

New regulations are never without critics and, unsurprisingly, some groups have a problem with the new laws.

Medical marijuana users and suppliers in Oregon, for example, have said that Washington's limit of 5 nanograms per milliliter of blood is far too low, making criminals out of most people who smoke even just a small amount and then get behind the wheel.

"There's no science behind that number," Dave Slack, owner of a medicinal marijuana told The Oregonian. "We're talking such a minute amount to make most patients basically criminals."

"With this rule, per se, I'm always going to be driving impaired," Steve Sarich, a Seattle resident and medical marijuana user, told The Oregonian. "Being treated like a criminal for driving? That's certainly not what I would call legalization."

Authors of the law, however, have cited numerous scientific reports, including a large Australian study of 3,400 fatal crashes that found driving risk increases when a person has between 3.5 and 5 nanograms per milliliter of THC in their system.

Worries about having stoned-out drivers on the roads have pushed associations representing police in Vermont to urge lawmakers to reconsider decriminalizing marijuana, T he Burlington Free Press reported.

"Unlike alcohol, science has not yet determined a presumptive level for marijuana nor has it developed a roadside testing procedure," the groups wrote in a letter to legislators.

While there is disagreement about how much pot is too much to drive, there is even less consensus on how long one should wait after burning one before operating a vehicle.

Research from NHTSA has shown that "marijuana has been shown to impair performance on driving simulator tasks and on open and closed driving courses for up to approximately three hours," but some experts argue that three hours still isn't long enough to rid THC from one's system.

Steve Graham, an attorney in Spokane, told Edmunds that tokers should wait up to 10 hours before they drive.

All in all, until some sort of consensus is reached by the experts, drivers need to wait until they're clear-headed enough to drive, which of course can often be hard to judge. So, the most surefire way to do that is to get a good night's sleep and be very careful on the road Jared Adams, a Denver attorney, told Edmunds.

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