Criticism of three-phase traffic theory

After introducing the history and main points of three-phase traffic theory, we continue with a critical discussion based on its theoretical features and empirical traffic data. Our data originate from the German freeway A5 close to Frankfurt, i.e. from the same freeway section that has been the basis for the development of three-phase traffic theory. Despite of this, we end up with partially different interpretations of the observations. In particular, we highlight findings that are inconsistent with three-phase traffic theory and facts that question the concept of a "general pattern" of congested traffic flow. Finally, we discuss some open problems that call for the development of improved traffic models and further empirical studies.