A recent study suggests that drinking alcohol and smoking marijuana has a more negative impact on a person’s ability to drive than just one or the other. But this seems logical. Maybe of greater importance, the study also suggests what defense attorneys have argued regarding marijuana use and driving. People who regularly smoke marijuana are less impacted by smoking than those who are not regular smokers. Unfortunately, in Colorado, the legislature has set the presumptive level at 5 nanograms per liter of THC. This presumptive level applies to all drivers regardless of their individual marijuana use. In addition, the study suggests that having 13.1 nanograms per liter of THC impairs a driver to same degree as a driver with a 0.08 BAC. Obviously, this is a much higher level than 5 nanograms.
This presumptive level is different than the per se level associated with the drunk driving law. In Colorado, if a driver’s BAC is 0.08 or more, then the driver is guilty of DUI per se. In contrast, the presumption related to stoned driving means a jury may presume the driver was under the influence, but are not required to make the presumption. This is important as it relates to the study because a defense to a DUID charge may be based on the individual driver’s smoking habits.
On the one hand, it seems detrimental to drivers that the legislature has created a presumption at a level that may be too low. On the other hand, at least it is a presumption and not a mandate. A driver could have 5 or more nanograms per liter of THC and a jury can acquit the driver if the defense presents information to rebut or refute the presumption. Assuming a jury follows the law, if a jury is convinced beyond a reasonable doubt that a driver’s BAC is 0.08 or more, the jury must convict of DUI per se.
Additionally, because the stoned driving level is only a presumption, at this time, DMV does not immediately take action to revoke a driver’s driving privilege. When a person has an alcohol related DUI with a BAC of 0.08, DMV will immediately set into action the process to revoke the driver’s driving privilege. This is also true if the driver refuses a blood or breath test (a blood test is required when testing for drugs) even if the officer believes the driver was under the influence of drugs. If, however, a driver takes a blood test in a DUID case, then regardless of the results, DMV will not take immediate action.
This does not mean DMV cannot revoke a driver’s driving privilege when he/she is charged with DUID and agreed to a blood test. If that driver takes a conviction for a DUI, then DMV may begin the process to take away the driving privilege.
To make matters more complicated, if a person’s license is revoked, in order to reinstate their license, he/she must install an interlock device in their car. Interlock devices only test for alcohol, but even if the driver’s DUI only involved marijuana, DMV will require the interlock.
Source: https://www.usatoday.com/story/news/2015/06/23/marijuana-drivers/29155165/