The tenth and last part again briefly describes the entire subject matter by reference to the objects of the literature study mentioned in the first part. This is mainly a matter of the conclusions and a mention of the research linked with existing knowledge and apparently applicable. Firstly traffic flow characteristics are discussed. It is important that when the characteristics are used they should be clearly defined and that attention is paid to any differences between formal definition and operation. The entire collection of traffic flow models, i.e., the descriptions of interactions between traffic flow characteristics, is discussed again briefly. Much of the required research consists of determining the validity of the models with the aid of actual traffic data. Promising types are the macroscopic dynamic models, because of their importance to dynamic traffic surveillance and control systems, and the microscopic simulation models, because these allow a more realistic description of vehicle movements than the less detailed models. The extraneous factors influencing traffic flow are the demand for use of roads, road characteristics, permanent vehicle characteristics, circumstances and countermeasures directly influencing vehicle movements. A brief sketch is given of the expected influence of each individual factor and which has also been partly confirmed in research. Lastly, the relationship between traffic flow characteristics and traffic flow quality is discussed, limited to traffic operation and safety. The main results are the relationships demonstrated between level of service, hourly volume and speed distribution and number of accidents for the distance covered. For part I-IX see IRRD abstracts nos 240606-240609 and 261941-5.
Abstract