Federal Report: “No Evidence-Based Methods to Detect Marijuana-Impaired Driving”
A federal report has determined that there is currently no evidence-based method of detecting marijuana-impaired driving, despite numerous states having laws in place that find someone guilty of a DUID if they test above a certain THC level.
“A number of states have set a THC limit in their laws indicating that if a suspect’s THC concentration is above that level (typically 5 ng/ml of blood), then the suspect is to be considered impaired,” states the report conducted by the National Highway Traffic Safety Administration (NHTSA) . “This per se limit appears to have been based on something other than scientific evidence. Some recent studies demonstrate that such per se limits are not evidence-based.”
In addition the report also calls into question sweat, hair, saliva and urine testing, stating that “there are currently no evidence-based methods to detect marijuana-impaired driving”.
The report notes that “Subjects dosed on marijuana showed reduced mean speeds, increased time driving below the speed limit and increased following distance during a car following task”. Alcohol, in contrast, “was associated with higher mean speeds (over the speed limit), greater variability in speed, and spent a greater percent of time driving above the speed limit. Marijuana had no effect on variability of speed.”
The report released by the NHSTA was mandated by Congress last year. The full 44-page report can be found by clicking here.
