“Researchers examined data on more than 44,000 drivers in single-vehicle crashes who died between 1999 and 2009. They found that 24.9% tested positive for drugs and 37% had blood-alcohol levels in excess of 0.08, the legal limit. Fifty-eight percent had no alcohol in their systems; 5% had less than 0.08.”
“But in 2007, the National Roadside Survey found that 16% of nighttime weekend drivers tested positive for illegal drugs.”