Survey shows more drugged drivers than drunken drivers in California on weekends Survey shows more drugged drivers than drunken drivers in California on weekends. A statewide survey shows there are more drugged drivers than drunken drivers on California roads during the weekend. The California Office of Traffic Safety said Monday that 14 percent of drivers surveyed tested positive for driving under the influence of illegal or prescription drugs. A little more than 7 percent of drivers were driving with alcohol in their system. The Los Angeles Times says the federally funded impaired driving survey involved more than 1,300 drivers who voluntarily provided breath and-or saliva samples at roadside locations in nine California cities on Friday and Saturday nights. Samples were tested for alcohol, marijuana and illegal drugs as well as prescription and over-the-counter medications. Marijuana was most prevalent with 7.4 percent of drivers having it in their system.