After years of debate and six unsuccessful votes, Colorado becomes the first state to set forth specific limits for THC use while driving. Lawmakers settled on the controversial 5 nanogram per milliliter of blood limit to establish that a driver is impaired by marijuana while driving.
The bill is on its way to Governor Hickenlooper to sign along with a host of other proposals regulating marijuana sales and taxation. The new laws come as a result of the voter approved Amendment 64, which legalizes the recreational use of marijuana in Colorado.
House Bill 1317, requires that retail marijuana outlets be licensed by the state and owned by Colorado residents. It also limits new entrants into the market to current medicinial marijuana dispensaries. House Bill 1318 imposes a 15 percent excise tax and a 10 percent sales tax on products sold. The excise tax would be used to support school construction, while the sales tax would go towards regulation of marijuana shops.
However, the centerpiece of all the marijuana regulation bills was House Bill 1325. In providing a criminal offense for impaired driving through THC, the bill still requires law enforcement officers to have probable cause to stop suspected drivers in the same way they would contact drunk drivers. Those arrested would still have to consent to having their blood tested, but they could face administrative penalties (e.g. having their license suspended) if they do not comply.
Ultimately, the application in the courtroom is what will matter. Juries will essentially be able to infer that drivers with more than 5 nanograms of THC per milliliter of blood were too high to drive.
Source: DenverPost.com, Colorado legislature gives final OK to marijuana driving limit, May 8, 2013