In this June 28, 2017, file photo, marijuana plants grow at the Desert Grown Farms cultivation facility in Las Vegas. A new report finds that legalizing and taxing marijuana boosts revenue for state and local governments, but not by much. The credit rating agency Moody's Investor Service says in a study released Tuesday, May 8, 2018, that legalizing recreational use of marijuana brings governments more money than it costs to regulate it.

How many Coloradans are driving high? New report offers one answer

Four years after the legalization of recreational pot sales, state officials are another step closer to determining how the change is affecting the safety of Colorado’s roads — but many obstacles remain.

About 73 percent of some 4,000 drivers charged with driving under the influence in 2016 tested positive for marijuana, according to a new Division of Criminal Justice report. Of those who tested positive, about half of the drivers had more than the legal limit of Delta 9 THC — marijuana’s chief psychoactive compound — in their blood.

But the study also reveals a criminal justice system not prepared to deal with drugged driving. The authors of the report noted that inconsistent testing is one of the many challenges in collecting data on drug-impaired driving.

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