If you get caught driving with a blood alcohol content of .08 percent, you’ve got a big problem. Under the law, you’re drunk. If you refuse to blow into the breathalyzer, your license is automatically suspended and you’ll be charged. You might be able to beat a DWI at trial, but you will pay a pretty penny.
If you smoke weed, the law is much murkier. It’s illegal to drive while your ability is impaired by drugs. But how do you know someone is “high?” You can do a blood test for THC, the psychoactive chemical in marijuana, but how much is too much?
The issue of marijuana impairment was front and center at a the vehicular manslaughter trial of John Ariano, accused of running a stop sign and killing Jack Blair. From my report on 13WHAM News:
Judge Frank Geraci, who presided over Ariano’s bench trial, found him not guilty of all charges. Geraci said there was not enough evidence the drugs in Ariano’s system caused him to be impaired and led to the crash. None of the deputies and other witnesses noted he was impaired. Ariano had been driving well under the speed limit and a driver who followed him for 7 miles didn’t notice any erratic driving.
“There was no impairment,” said Christopher Schiano, Ariano’s attorney. “It was not a popular verdict, but it was the right one.”
Schiano said his entire case was built around the fact New York State doesn’t have a threshold for how much marijuana a driver can have in his system. He said this was a rare vehicular manslaughter case because it didn’t involve any alcohol use.
Prosecutors alleged Ariano had 5.4 nanograms of THC in his blood. Colorado lawmakers recently defeated a bill that would have made 5 nanograms the driving threshold. The Denver Post reported:
At the earlier committee hearing, medical-marijuana activists argue that the proposed limit — 5 nanograms of THC per milliliter of blood — is too low and would result in near-certain convictions for sober drivers.
The bill’s opponents argued that medical-marijuana patients have no way of determining what 5 nanograms means. How much can they consume? How long do they have to wait afterward?
Supporters of the bill counter that the vast majority of people would be impaired at 5 nanograms and would need to wait only about two to three hours after using to fall below the limit. They argue that, even though some people could be sober at 5 nanograms, it is important to send a strong message.
Michigan prohibits any amount of marijuana in a driver’s blood.
While it’s widely accepted that alcohol impedes one’s ability to drive, the jury is out when it comes to marijuana. A Bloomberg columnist who is opposed to a marijuana threshold reports:
…when drivers are under the influence of THC; they tend to have heightened awareness — rather than diminished sensitivity as they do after drinking — to their surroundings. As a result, they tend to compensate by driving more cautiously.
A 2007 control study published in the Canadian Journal of Public Health reviewed 10 years of U.S. auto-fatality data. Investigators found that U.S. drivers with blood-alcohol levels of 0.05 percent — a level below the national 0.08 percent legal limit — were three times as likely to have been driving unsafely before a fatal crash, compared with individuals who tested positive for marijuana.
We will likely see more drugged driving cases. Rochester defense attorney Ed Fiandach said police are stepping up enforcement and getting more training. Much of the focus has been on drivers high on prescription drugs, but the Ariano trial shows marijuana users can also get nabbed.
It’s clear more research is needed on the impact of marijuana and other drugs on driving.