Providence police test for marijuana DUI primarily through officer observations, field sobriety tests, and blood or urine testing. Unlike alcohol, there is no roadside breathalyzer for marijuana, and the body metabolizes THC much more slowly than alcohol, complicating the relationship between test results and actual impairment at the time of driving. Drug Recognition Experts (DREs) trained in identifying drug impairment may be called to the scene or station. Blood and urine tests can show THC presence days after consumption without proving current impairment, which is a key defense angle in marijuana DUI cases.
