With the rise of legal marijuana comes an increase in the number of stoned drivers, and researchers at Washington State University are working to give police officers a tool in determining who's high and who's not high: A simple breath test, reports the Tacoma News-Tribune. It's no small matter: Of all drivers given blood tests last year—the first full year of legalization—a quarter tested positive for marijuana. Scientists are hoping to harness existing technology to develop a simple handheld device that can detect THC on a person's breath.
A rep with the Washington State Patrol says that while they "welcome anything that will help us get impaired drivers off the road," that the breath test would need "to be rock solid before we'll adopt it." That "rock solid" part may be a while in coming: The device WSU is working on will detect THC, but not necessarily the amount present (the state's current limit is 5 nanograms of active THC per milliliter of blood, notes the News-Tribune.) Still, such a device could help an officer determine whether to make an arrest and obtain a blood test to measure the level of THC. (Meanwhile, a new study found that chronic pot smokers have different brains.)