Washington State DUI laws have a legal limit for alcohol .08. Over the last 100 years there has been a lot of research linking alcohol consumption to physical and mental impairment. Did you know a few years ago Washington State DUI laws added a legal limit for marijuana intoxication? That limit is 5 ng of THC (Tetrahydrocannabinol), which is the chemical responsible for most of the impairing effects of marijuana. Compared to alcohol there is significantly less research on the quantity of THC in one's blood that is necessary to impair physical and/or mental functions.
One of the difficult things about legal limits for DUI's is that these laws allow folks who are over 21 years old to have some alcohol and/or THC in their body while driving, but knowing whether one is "over the limit" for DUI purposes can be difficult. There are different rules for those under 21 years of age for both alcohol and THC. When it comes to alcohol we've all heard of the "beer an hour rule" which stands for the concept that having no more than one 12 oz standard beer (approximately 4% alcohol) per hour should keep someone under the alcohol limit for DUI. Unfortunately, there is no comparable rule for marijuana and THC. Those who consume marijuana and other products containing THC, whether lawfully or unlawfully, and who drive in Washington State are at risk of being over the THC limit simply because there isn't anything like a "joint an hour rule."
The State of Utah recently reduced their legal limit for alcohol down to .05. Are legal limits allowing drivers to have some amount of alcohol and/or THC in their system a good thing? Should the State of Washington remove the guess work for drivers and simply require no alcohol or THC in the body when driving?