A recent article states that the AAA Safety foundation has noted that after Washington state legalized marijuana for recreational use in 2012, the number of fatal accidents involving drivers who’d recently used pot more than doubled between 2013 and 2014.

Because there’s currently no test that can be given to determine the exact amount of marijuana in an impaired driver’s bloodstream, the researchers are suggesting that additional training for law enforcement to recognize the signs of impairment due to marijuana use.

Impaired DrivingThe AAA foundation’s director of research, Jake Nelson, spoke about why testing drivers for the amount of marijuana in the bloodstream isn’t effective, “Biologically, cannabis and alcohol are very different. I think policymakers trying to do the right thing are trying to establish something like a .08 for cannabis, and there’s just not science to support it.”

According to the CDC, marijuana users are about 25% more likely to be in a car accident than others who did not use it, but factors such as age and gender may also play a role in increased accident risk.

Currently, there are about a dozen states that are considering legalizing marijuana.