Samenvatting
The range of applicability of some traffic flow models is discussed on the basis of experimental data obtained on different roads in the ussr. Each traffic flow model was found to be practicable only for a certain traffic volume. Through the analysis of the range of applicability of the various traffic flow models the boundaries of different traffic flow states and various levels of service were found. Knowledge of such boundaries is especially important for traffic flow simulation on digital computers and for defining the optimal levels of service which should be provided on roads. (a) for the covering abstract of the symposium please see irrd abstract no. 224453.