The rules for driving under the influence of alcohol are pretty cut and dried. Those drivers whose test results showed a blood alcohol concentration (BAC) of .08% or above are considered too impaired to drive. The driver is then charged with a DUI.
Because there is no standardized test, driving under the influence of marijuana is more difficult to measure and penalize even though the general threshold is five nanograms or more of tetrahydrocannabinol (THC) in the blood. Regardless, there is no scientifically valid number indicating intoxication or impairment because each person reacts differently to the drug, and regular users build up a tolerance. Gender and the amount of body fat can also come into play.
Officers must use their judgment
Most law enforcement here in Colorado are trained to identify drivers impaired by marijuana. The behaviors and circumstances include:
- There is erratic driving with varying speeds and weaving out of the lane.
- There are marijuana products within reach of the driver.
- The driver or vehicle smells of marijuana.
- The driver’s eyes are bloodshot or dilated.
- The driver acts impaired.
Agencies may also rely on drug recognition experts to determine intoxication.
Penalties are similar
Even if there are differences in determining intoxication, the penalties for DUI or DWAI (the lesser charge of driving while ability impaired) still apply to drivers who consume marijuana. For this reason, drivers should be aware that they are at risk of impairment if they use marijuana products. The good news is that rules are subjective if there is no overriding evidence of use or intoxication. When an attorney defends the driver in court, these variables can come into play.