(NBC News) Blood tests can clearly show if a person is too drunk to drive, but the same may not be true for tests to determine if a driver is too high.
A new report by the American Auto Association (AAA) has found that the percentage of drivers who are high on pot during fatal accidents in Washington State more than doubled between 2013 and 2014.
In Washington, only looking at crashes in which at least one driver tested positive for active THC, there were 40 fatalities in 2010, compared to 85 in 2014, according to AAA estimates. However, a large number of drivers were not tested for THC or did not have available blood test results, so THC-related fatalities could be much higher, the report notes.
The AAA report focused only on Washington state, while legalized the sale and possession of marijuana in 2012. It did not track driving while high fatality trends in Colorado, which also legalized pot that in 2012.
But with marijuana on the ballot to become legal in more states, AAA researchers fear that the numbers will rise more sharply.
Six states, Colorado, Ohio, Pennsylvania, Montana, Nevada and Washington, have set a legal threshold for how much marijuana can be detected in the blood before a person is considered too impaired to drive, but AAA says those blood tests are not based on sound science.
“It’s completely arbitrary. There’s no research study. There’s no relationship,” says AA Director of Traffic Safety Advocacy and Research Jake Nelson. “There’s nothing to support setting a numerical concentration of cannabis in somebody’s body that would allow us to predict that they are impaired.”
Marijuana affects people in different ways and experts say some smokers with more evidence of pot in their system may be less impaired than others who’ve smoked very little.
AAA argues some drivers might be wrongfully convicted, while others may be going free when they’re really unfit to drive.
“The debate isn’t if it impairs, the debate that exists is to what extent?” Nelson explains. “How much do we consume, and how is that related to how impaired we are behind the wheel?”
AAA suggests police officers could be specially trained to determine a driver’s impairment, with blood tests as a back-up.
Read more: http://nbcnews.to/1ZCdWgC