The facts about Driving Under the Influence of Marijuana

When most people think of “DWI” and “DUI” they generally relate it to alcohol. But with an ever-increasing number of states legalizing marijuana, either for the medical or recreational purposes, law enforcement is focusing on driving under the influence of marijuana. For example, Colorado has legalized small amounts of marijuana for medical use and it appears that prescriptions for it are ever increasing. That said, so are the DWI and DUI arrests increasing there because of marijuana use.

Driving Under the Influence of Marijuana in Texas versus other states

Unlike Colorado, Texas DWI and DUI laws make simple possession of marijuana illegal. But like Colorado, Texas does make it illegal to operate a motor vehicle while intoxicated by marijuana. Interestingly, law enforcement in Colorado and in Texas have seen a dramatic rise in the number of DWI and DUI arrests due to marijuana intoxication.

Texas DWI and DUI laws make it illegal to operate a motor vehicle in a public place while intoxicated and illegal to possess marijuana. In regard to DWI, Texas law defines intoxication as:

“… not having the normal use of mental or physical faculties by the introduction of alcohol, a controlled substance, a drug, a dangerous drug, a combination of two or more of those substances, or any other substance into the body.”

This definition covers driving under the influence of marijuana case because it includes someone who lost the normal use of his or her mental or physical faculties by the introduction of marijuana into that person’s system.

Measuring intoxication and “No Refusal” programs

Currently, police labs measure alcohol by having the accused citizen submit to either a breath test or a blood test. Neither the Intoxilyzer 5000 nor the Intoxilyzer 9000, which are the machines used in Texas to quantify breath/blood alcohol concentration, can detect tetrahydrocannabinol or “THC”, the active ingredient in marijuana. However, a blood test can.

Accordingly, many counties in Texas have started to focus on blood testing in DWI and DUI investigations where marijuana is suspected as the intoxicant. Indeed, many counties have obtained grants to fund “No Refusal” programs where police obtain search warrants to take blood samples. This sample is then analyzed to obtain a measurable amount of alcohol or other substances, like marijuana, that may be in a person’s blood.

DWI and DUI of Marijuana and Per Se Definitions of Intoxication

In addition to the “loss of the normal use of mental or physical faculties” standard, Texas law provides that a person is considered intoxicated if that person has a BAC of 0.08 or higher, regardless of whether that person has lost the normal use of his or her mental or physical faculties. Some states have started to include a similar “per se” definition of intoxication regarding marijuana.

In Colorado and Washington, where recreational use of marijuana has been legalized, that limit is five nano-grams per milliliter of blood, or five parts per billion. Texas has no “per se” definition of intoxication by the introduction of marijuana into the system, so courts and prosecutors look at this on a case-by-case basis. Note that because recreational use of marijuana is not legal in Texas, many prosecutors and judges often look harshly upon any detectable amount of THC found in the driver’s blood.

Also, looking to the future, there are many instruments being tested now for use of police on the road side that will test a person’s saliva for both identification and quantification of THC. These road side saliva tests will most likely be in Texas in the near future.

And so, our advice is not to drive if you consumed any alcohol or any marijuana. A taxi cab fee is much cheaper than that of the bondsman and lawyer. Should you have any questions, please feel free to contact us at 713-524-1010  or contact us here.