There are two major factors responsible for the way contemporary cities look the way they do. One is the ever-increasing volume of traffic, and the other is the present commercial culture which manifests itself most visibly through advertising. This paper deals with the effects of advertising in a city environment; the main focus is on advertising linked to traffic. Nowadays we have become so accustomed to advertising that it sometimes is actually hard to recognize just how much is around. Spaces without some form of advertisements are becoming progressively fewer in today's Western cities. The city-dweller's field of vision is dominated by commerce. Public transportation is a prime example of this condition. Contemporary advertising techniques have made it possible to turn cars, trains, trucks, busses and planes into moving billboards. The commercial culture produces cities which are dominated by something I call "economist's aesthetics."