Last November, voters in Colorado passed a ballot measure that legalized the use of recreational marijuana in the state. Adults in Colorado are now allowed to possess and grow small amounts of marijuana for personal use. Once the state figures out a regulatory framework, Coloradans may also be able to buy and sell marijuana at retail establishments.

Sales aren’t the only issue that needs to be worked out, though. Many people are concerned that legalizing marijuana could lead to a dangerous surge of stoned drivers on Colorado roads. In response to this fear, state lawmakers are working on legislation that would set a threshold at which marijuana users would be deemed “too stoned to drive.” Stoned driving would be treated the same as an alcohol-based
DUI offense.

The current initiative marks the fourth time state lawmakers have tried to agree on "stoned driving" regulations. On February 26, 2013, the bill was approved by the House Judiciary Committee, marking an important step forward for its passage.

The current version of the bill sets a threshold of 5 nanograms of tetrahydrocannabinol (or THC, the active ingredient in marijuana) per milliliter of blood. This is the same threshold used in Washington state.

The bill has drawn opposition from marijuana advocates, who say that the 5 nanogram limit is too low. Some people – especially regular users of marijuana -aren’t actually impaired at this level.

Of course, this is true when it comes to drunk driving as well. Some drinkers are relatively functional with a 0.08 blood alcohol content while others are significantly impaired at a much lower level.

The proposed stoned driving law, though, offers potential defendants an opportunity to contest their impairment. If the bill passes, Coloradans arrested on suspicion of driving under the influence of
marijuanawould have the option to show that even though their blood THC concentration was over the legal limit, they weren’t actually impaired to the point of being an unsafe driver.

Colorado intoxicated driving arrests

A lot of the confusion around Colorado’s proposed stoned driving law comes from the fact that there is still very little scientific evidence regarding the effects of marijuana intoxication on driving ability.

Still, if the law passes, it is likely that law enforcement will police stoned drivers much like they do drunken ones. The highway patrol and local law enforcement departments will watch for drivers who appear to be driving in an erratic or dangerous manner, and will pull them over if there is reason to believe that driving laws are being violated. If the traffic stop reveals evidence of marijuana intoxication, law enforcement will be able to administer roadside sobriety tests and possibly make an arrest.

Even if lawmakers do not include a provision in the law allowing defendants to challenge the personal application of the intoxication threshold, there will still likely be several avenues to challenge the validity of a traffic stop or intoxicated driving arrest. For example, there may not have been probable cause to believe that driving laws were being violated. Or, perhaps law enforcement obtained evidence in violation of the defendant’s constitutional rights.

There are a number of different ways to defend against Colorado intoxicated driving charges. However, many of them are time-sensitive. For that reason, it is important to contact an experienced criminal defense attorney as soon as possible after an arrest. The attorney will be able to review the case and advise on the best options for moving forward.