11/26/2012 07:32 pm ET Updated Nov 27, 2012

Drugged Driving More Prevalent Than Drunk Driving, Study Finds


Drugged driving has become more prevalent on California roads and highways than drunk driving, a study released earlier this month by the state's Office of Traffic Safety found.

The report, which looked at the drug and alcohol test results of weekend, nighttime drivers in California found that 14 percent tested positive for drugs known to impair driving ability. Just under 7.5 percent of the same group tested positive for alcohol.

"These results reinforce our belief that driving after consuming potentially impairing drugs is a serious and growing problem," Office of Traffic Safety Director Christopher Murphy said in a statement.

Nearly a quarter of drivers who tested positive for alcohol had also consumed another drug.

Pot was the most commonly found drug present in the tests, which used a measurement able to determine if marijuana had been ingested in the past few hours (in contrast to other tests for cannabis that can test positive weeks after consumption).

The study analyzed breath and saliva samples voluntarily provided by 1,300 drivers at roadside locations in nine cities across the state. The samples were collected between 10 p.m. and 3 a.m. on Friday and Saturday evenings, the times when drunk and drugged driving are most likely to occur. They screened for alcohol, marijuana and other illegal narcotics as well as prescription and over-the-counter drugs known to negatively affect driving.

The Orange County Register reports:

[The Office of Traffic Safety] commissioned the $650,000 study by the Maryland-based Pacific Institute for Research and Evaluation, paid for with federal funds. It initially questioned whether such a voluntary survey would accurately reflect the problem: Would a driver high on cocaine, for example, agree to stop and talk about it? But Cochran said the participation rate was so high, even among drivers who initially wanted no part of it, that the study's authors determined it was statistically sound.

ABC Sacramento noted that Mothers Against Drunk Driving recently increased its focus on drugged driving. "Driving under the influence no longer means just alcohol," said MADD California Program Manager Silas Miers. "It includes alcohol and drugs and a combination of both. The result and the consequences are really the same. People get arrested or they end up dead."

Earlier this year, California Governor Jerry Brown signed a bill into law that sorted drugged driving, drunk driving and driving under the influence of both drugs and alcohol into separate offenses. That law goes into effect at the end of next year.

A national survey among fatally injured conducted by the National Highway Traffic Safety Administration in 2010 found that one-third of said victims tested positive for at least one drug.