) -- Car drivers face a growing dilemma these days as more and more states liberalize marijuana laws -- making it unclear what constitutes "D-W-High," or driving while high.
"I can remember when people used to say: 'I'm actually a better driver when I've had two martinis.' I'm seeing the same thing now with pot," says Steve King, a Colorado state senator who's sponsoring a bill to use blood tests in his state to define so-called "drugged driving."
Colorado and Washington State recently legalized recreational pot and Massachusetts became the 18th state to OK medical marijuana, but there's no consensus on how soon someone can safely or legally drive after toking up. Studies have reached different conclusions, while states have various drugged-driving standards.
King, a Republican lawmaker and local deputy sheriff, wants Colorado to join 14 states that define D-W-High as driving when your blood contains a specific amount of tetrahydrocannabinol. Known as THC, tetrahydrocannabinol is the active ingredient in pot.
But the National Organization for Reform of Marijuana Laws, a pro-legalization group, claims there's no scientific consensus on what blood-THC levels impair drivers.
"We need to understand that the pharmacokinetics of cannabis are very different from alcohol," NORML's Paul Armentano says.
For instance, Armentano says that while alcohol enters the bloodstream slowly through the digestive tract, THC immediately hits a pot smoker's arteries via the lungs. That means users can have hefty blood-THC levels even before marijuana takes effect, but lower amounts even when people are still high, he says.
As such, NORML argues that states should use only blood tests in conjunction with other drugged-driving evidence.
Lenny Frieling, a Boulder
who heads NORML's Colorado chapter, believes courts should look mostly at such things as how suspects perform in roadside impairment tests. "Blood tests are just one piece of the puzzle," he says.