How high is too high to drive? Lawmakers postpone complex debate

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DENVER -- Colorado lawmakers were expected to introduce a bill today seeking to set a limit on driving while high for the fourth time. But shortly after 9 a.m., the debate on that bill was postponed.

According to FOX31 Denver political reporter Eli Stokols, the vote was delayed because lawmakers want to turn their focus to gun legislation first.

As testy as the debate on proposed new gun laws has been, the upcoming debate on driving high is expected to be just as heated.

State legislators have failed to agree on a driving blood limit standard for marijuana on three separate occasions. The reason? Many of the studies being cited by each side seem to contradict each other.

We performed one of those studies last May. And the results were just as complex.

Want proof that there were those who disagreed with our findings? Click here.

In our study, volunteers not only let us test their driving skills with a high-tech simulator, but their THC levels before and after using marijuana, as well.

The general consensus of the study: Determining who is too high to drive is all variable on the person.

Still, there are some, like Republican House Rep. Mark Waller, who think making that determination is an important one.

"This is absolutely about public safety," Waller said. "If you're intoxicated you shouldn't be out on the roads."

Right now, it's illegal to drive stoned. But prosecutors must prove impairment in each case. The current proposed standard that will be debated by a House committee on Thursday suggests that if you have 5 or more nanograms of Delta 9 THC in your system, you’re too high to drive.

The idea is to enforce the proposed limit similarly to the .08 blood alcohol level for alcohol -- meaning if a driver has 5 nanograms or more in their blood, they would be arrested for DUI.

The desire to set a standard for driving high is one that has its roots in the community, according to Waller.

"Juries expect and want to see limits on driving under the influence,” he said.

Our test showed two of our volunteers would be considered impaired under the proposed state standard.

For one of the volunteers, her results came back clean. This was despite ingesting marijuana an hour before the test.  She admitted driving high impaired her driving, but under this new bill police wouldn't have arrested her.

It's cases like these that lead some experts to believe a 5 nanogram limit isn't the answer.

"I think there should be another way to base it on, not five nanograms because it affects everyone so differently,” phlebotomist Sarah Knill said.