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Vermont Legislature
Follow VPR's statehouse coverage, featuring Pete Hirschfeld and Bob Kinzel in our Statehouse Bureau in Montpelier.

Before Legalization, Scott Wants A Driver Impairment Test That Doesn't Exist Yet

Angela Evancie
VPR file
Gov. Phil Scott, shown here at a Statehouse news conference in November, wants a test that measures the specific amount of THC in a driver's system.

Gov. Phil Scott says he wants lawmakers to pass a marijuana driver impairment law before they consider a legalization bill. But transportation officials say the kind of test that Scott wants to use doesn't exist at this time.As one House committee considers a bill to legalize marijuana and another one looks at plan to enact new marijuana driver impairment standards, Scott is sending a clear message to the entire House.

"I believe that we should be determining level of impairment first, before we legalize,” he says.

The House Transportation committee is drafting a bill that would create a new level of driver impairment.

Currently, a driver is considered to be impaired if their blood alcohol level is .08 percent or higher. This bill would lower the limit to .05 percent if there was any trace of marijuana in the driver's system. 

"I believe that we should be determining level of impairment first, before we legalize." — Gov. Phil Scott

"So if you were to be stopped for erratic driving and you tested at .05 for alcohol with the presence of THC in your system, no specific level, then you would be deemed to be impaired,” says Colchester Rep. Pat Brennan, the chairman of the committee. 

But the governor doesn't think this House plan goes far enough. He wants a test that measures the specific amount of THC in a driver’s system. THC is the psycho-active ingredient in marijuana.

Scott has other questions as well.

"Just like if you have any alcohol it doesn't mean you're impaired, so what is the level of THC that causes impairment?" asks Scott. “I don't have the answer to that, I don't think we have a good way to measure that, and that's what I am seeking, trying to make sure that we have that in place before we move forward."

Rep. Brennan notes that a blood test and a salvia test can measure a person's THC level, but he says there's very little agreement on what constitutes a level of impairment because people metabolize marijuana very differently. That's why Brennan says it will be very hard to satisfy the governor's request.

"I think to pin something down as to the exact [THC] content in the system doesn't exist." — House Transportation chairman Pat Brennan

"I think to pin something down as to the exact content in the system doesn't exist. The test, as I said, tests for presence, but not content,” said Brennan.

Scott says the debate over impairment is a reason for the Vermont Legislature to move very cautiously on the legalization bill. He also wants to study how other states are dealing with this issue.

"I'm not sure what the other states are doing at this time but I think we have a perfect opportunity to find out,” said the governor.

Colorado and the state of Washington use a blood test to measure driver impairment. They set a level of 5 nanograms of THC as the "presumed" level of impairment, but this approach doesn't have the same force of law that an alcohol test has.

There are other ways to measure impairment.

There are roughly 40 drug recognition experts in Vermont who work for local, county and state law enforcement agencies. These DREs can be dispatched to evaluate a driver after the person has been pulled over for erratic driving behavior.

They're trained to identify all types of drug impairment, from prescription medications to marijuana. A determination of probable impairment can lead to a blood test.

Matt Simon is the director of the Marijuana Policy Project, a group that's working to legalize pot in Vermont. He thinks this system of expert evaluation is the best way to deal with the impairment question.

"Successful prosecutions are today and should be in the future based on observation of a driver actually being impaired and being able to demonstrate that impairment in court," said Simon.

Another factor for lawmakers to consider in this debate is the role of the federal government.

Recently, President Trump indicated that his administration might start cracking down on states that have legalized marijuana because possession of pot is still a federal crime.

Bob Kinzel has been covering the Vermont Statehouse since 1981 — longer than any continuously serving member of the Legislature. With his wealth of institutional knowledge, he answers your questions on our series, "Ask Bob."
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