For Stoned Drivers, a Rocky Mountain High

How high is too high? No one knows. That's why the Colorado Senate voted yesterday against a bill that could have given new meaning to DUI—driving while under the influence of marijuana—specifically imposing a five nanograms of THC per milliliter of blood limit. Had the bill passed, it would have been the nation’s first law singling out weed-impaired vehicle operators.

What sank the bill was science—or the lack thereof. There’s no scientific or medical evidence supporting a specific amount of THC as the level at which a driver’s driving becomes potentially hazardous. In addition, even some of the bill’s sponsors said that patients who regularly use pot for pain can have a blood level of 5 nanograms hours after using the drug—and even long after any THC high fades. Marijuana stays in the body much longer than alcohol does.

Sen. Kevin Lundberg, who agreed that more scientific evidence was needed to back the bill, said, “To say that you can use [marijuana] but you cannot drive ever—we have to be very careful when we go down that road.”