I don't believe that quotas are a real thing. I do believe that traffic tickets are are one factor in how a patrol officer's "productivity" is measured, especially in smaller departments. And DUI/narcotics arrests always look good when promotion time rolls around.
That having been said, it's been my experience in 26+ years in public safety that most cops are just like the rest of us. They want to come to work, do their jobs to the best of their abilities, then go home. Those guys & gals, however, don't make the evening news all that often.