The checkpoint was set up south of Santa Rosa Junior College at the intersection of College Avenue and Morgan Street, just east of U.S. Highway 101, police said.
Of the 1,506 vehicles that passed through the checkpoint on Saturday, 64 drivers required further screening of their driver's licenses and 39 were subjected to field sobriety exams, police said.
Eighteen people were found to be driving with invalid licenses and were arrested, police said. Five of the drivers were using suspended licenses and 13 had no license at all, police said.
Two suspects were arrested for driving under the influence, and one of them was involved in a hit and run prior to his arrest, police said.
That driver, 29-year-old Adam Hayden Clark of Petaluma, was driving with a blood-alcohol content of .23 percent - nearly three times the legal limit, police said.
Clark was driving down College Avenue when he hit the curb and struck a sign in front of 440 College Ave., police said. Clark did not stop after striking the property and was pulled over a short distance later by officers on motorcycles, police said.
Clark was booked into the Sonoma County Jail on suspicion of driving under the influence, police said.
The second person arrested for DUI was 28-year-old Ukiah resident Michael Kane, whose blood-alcohol content was just over the legal limit at .09 percent, police said.
Kane was taken to a secondary evaluation area after entering the checkpoint area and presenting "objective symptoms of intoxication," police said.
Kane was arrested, but then merely cited to appear in court and released to a sober driver, police said.
Police also made two arrests for public intoxication after people found to be under the influence walked either into the checkpoint area or onto the roadway, police said.
Two additional people who passed through the checkpoint were arrested when they were found to have outstanding warrants, police said. Those people were cited to appear in court.
Fourteen vehicles were also taken by police for 30-day impoundment, police said.
The last person arrested on Saturday night was 30-year-old Santa Rosa resident Sean Thompson, police reported.
Thompson was booked on charges of felony domestic violence after officers witnessed him committing acts of domestic violence near the intersection of College and Mendocino avenues, police said.
The checkpoint was funded by a grant from the California Office of Traffic Safety through the National Highway Traffic Safety Administration.
