Three DUI/license checkpoints will be set up tonight and extra police officers will be on duty this July 4th weekend as part of a stepped-up crackdown on drunken drivers in Sonoma County.

The CHP and Petaluma and Santa Rosa police each plan checkpoints tonight. Petaluma Police Sgt. Ken Savano, who coordinates local police efforts targeting DUI driver, said the checkpoints’ hours will vary but will be basically along the lines of 6 tonight to 2 a.m. Saturday.

He said each police agency in the county is expected to assign at least one additional officer to concentrate on looking for suspected DUI drivers. The CHP is sending out every available officer over the long weekend as part of its July 4th safety effort.

The crackdown is part of the Avoid the 13 Sonoma County DUI Task Force that involves all local police agencies.