Cops around the country are having a hard time figuring out if drivers are stoned. With drunk driving, a breathalyzer test can easily alert officers to heightened blood-alcohol content levels, but with weed, which stays in the body for up to a month, it’s damn-near impossible to determine if a driver lit up 10 minutes or 10 days before getting behind the wheel. 

Now, according to U.S. News, legislators in Nevada are trying their hardest to eliminate the DUI confusion and standardize the procedure for stopping stoned drivers. A new bipartisan bill making its way through the Nevada state house would require cops to take a blood test from suspected high drivers, and arrest them only if that blood sample turns up with a blood-THC level of 5 nanograms per milliliter or higher.

Blood tests are more reliable than urine samples when it comes to tracking an individual's cannabis use, but there’s still no foolproof way to determine if someone is actually under the influence of cannabis at any given time.

"There's still no proof that those standards mean anything, but at least we're moving to something which is scientifically provable," Las Vegas Sen. Tick Segerblom told reporters.

However, blood-THC levels of frequent users could stay higher than the allowed 5 nanograms per milliliter even if they’re driving completely sober.

The new legislation would improve the accuracy of cannabis-related DUI stops, but it still isn’t the answer law enforcement needs moving forward. Until there is a scientifically supported method for determining cannabis intoxication, cops will still be guessing and drivers will still have an easy argument in court.

Like taxation and other regulations, figuring out an appropriate way to handle stoned drivers will take time and effort, but is already far better than the total lack of oversight that came with prohibition.