What does traffic have to do with living in the city? You don’t drive when you live in the city, the traffic is from people in the suburbs coming into the city - you’re already here there’s no reason to drive. 
That very much depends on the city. I live in Los Angeles. It’s giant, and most people have to do quite a bit of driving. My personal commute is only 15 minutes by surface streets, but almost everyone I know has to take the freeways. My doctor is 15 miles, and traffic can change that from 20 minutes into an hour and a half.
What does traffic have to do with living in the city? You don’t drive when you live in the city, the traffic is from people in the suburbs coming into the city - you’re already here there’s no reason to drive. 
That very much depends on the city. I live in Los Angeles. It’s giant, and most people have to do quite a bit of driving. My personal commute is only 15 minutes by surface streets, but almost everyone I know has to take the freeways. My doctor is 15 miles, and traffic can change that from 20 minutes into an hour and a half.