How high is too high to drive with cannabis in your system?

Although Georgia lacks a statutory threshold to measure impairment for drivers arrested on suspicion of driving stoned, many consider one to be driving under the influence if their blood contains more than 6 nanograms of active tetrahydrocannabinol, or THC, the cannabinoid in marijuana that causes its coveted psychoactive effects. In Colorado, the legal limit has been set at 5 nanograms of THC, but problems arise when majiuana users, particularly those who partake regularly, test over the legal limit even when they are not impaired. This article explores the considerations at issue to accurately measure driving impairment for frequent pot users.