With the most lax marijuana laws in the nation, Colorado has been making headlines for some time now. Starting January 1, 2014 Colorado residents can legally purchase marijuana for recreational purposes. Until the law change, Colorado had only allowed residents to use the drug for medicinal purposes. Now, dispensaries can legally sell to anyone over the age of 21. With a great deal of regulation and certainly some skepticism, the legal weed market in Colorado appears to be booming. The first week of 2014 saw dispensaries and shops making approximately $5 million in sales. State officials expect to make roughly $70 million in tax revenue based on the 25% tax rate applied to all sales.

While the financial consequences certainly appear to benefit Colorado’s treasury and dispensary owners, what are the legal ramifications for high residents? First and foremost, only those over the age of 21 can buy the drug, and can only use it on private property. Even with those restrictions, some recreational users will find themselves on the wrong side of law if they smoke or ingest marijuana and drive. Due to the change in the drug law, the state legislature saw the need to revise DUI laws to account for the potential uptick of drivers under the influence of marijuana.

Currently, Colorado law still maintains the illegality of driving under the influence of marijuana. However, drivers and passengers can transport marijuana within the state if it is in a closed container, similar to laws regulating the transportation of alcohol. Drivers may not smoke or ingest marijuana while they are operating a vehicle. Blood tests for THC (the “get you high” chemical in marijuana) cannot necessarily limit the time frame of the results. That is, anyone who has used marijuana in the days or even weeks leading up to a blood test may test positive without having used that day. This is somewhat problematic for drivers who regularly use marijuana, but may not have used before or during their drive. For this reason, Colorado actually now uses more accurate blood tests to reveal active THC in a person’s blood, to narrow down the time frame they last used. The law presumes that anyone with five nanograms or more of THC per milliliter of blood while driving can be charged with a DUI.

Like most states, drivers can refuse the blood test. However, like in most states, refusal of the test can lead to severe penalties. In Colorado, refusing to submit to a blood test will lead to a license revocation for one year of the first refusal and additional years for subsequent refusals. If convicted of the DUI, a first time offender faces jail time of at least five days (but not more than one year), a fine between $600 and $1,000, between 48 and 96 hours of community service, and possible probation.

To stem a potential influx of marijuana-related DUIs, Colorado is partnering with the National Highway Traffic Safety Administration (NHTSA) to campaign against driving while high. The NTHSA, a federal agency, has granted $400,000 to the Colorado Department of Transportation for advertisements aimed at preventing DUIs. Additionally, the grant may be used to train more police officers to become drug recognition experts and thus be able to spot illegal drug use more easily. Time will tell how many Colorado drivers decide to get behind the wheel while high, and whether the media campaign will help prevent that.