The California Office of Traffic Safety has launched a campaign aimed at the rise in people driving while high on drugs.
Last month, California voters legalized the use of recreational marijuana.
The "DUI Doesn't Just Mean Booze" campaign highlights the consequences of using prescription and illegal drugs while operating a vehicle.
Rhonda Craft, director of the Office of Traffic Safety, said most people understand the consequences of driving under the influence of alcohol, but the same can't be said about drugs.
"You'll have people who are on prescription medications who think that because it was prescribed by a physician, they might be OK, but they need to pay attention to those labels because if it says 'do not drive or do not lift heavy machinery,' a vehicle is heavy machinery. And if you're caught driving impaired, you will be arrested for DUI," Craft said.
In 2012, more drivers tested positive for drugs than alcohol, according to the Office of Traffic Safety. Marijuana was the most common substance among those driving while impaired.
Unlike alcohol impairment, there is no national standardized test for driving under the influence of drugs.
The Office of Traffic Safety says medications such as pain killers, muscle relaxants and sleep aids can impair driving.
"A lot of people don't realize that prescription drugs, if taken the wrong way, if taken with alcohol, there's this synergetic affect and the impairment becomes very pronounced. And now with the introduction of medicinal marijuana and now legal marijuana, we're starting to see an increase of impairment in people smoking marijuana," says Joe Farrow, commissioner of California Highway Patrol.
In 2014, 38 percent of California drivers killed in car accidents tested positive for drugs, according to the National Highway Traffic Safety Administration.
