Five people were arrested on suspicion of driving under the influence as part of a multi-agency saturation patrol during the holiday weekend, police said.
Fourteen officers from the California Highway Patrol and Glendale, Burbank and San Fernando police departments took part in the operation.
Officers stopped four motorists on suspicion of drunk driving and another for allegedly being under the influence of marijuana and the prescription drug Xanax.
Motorists had the option of measuring their blood alcohol level by blowing into a breathalyzer or having their blood drawn by a phlebotomist who was on site with police.
Three motorists opted for the second choice — likely because they can also request a sample of the blood, which their attorneys can later have tested by an independent laboratory, Glendale police Sgt. Harout Bouzikian said.
Law enforcement agencies across Los Angeles County arrested about 685 motorists on suspicion of DUI from July 4 to Sunday. Last year, that number was 503.