Abstract
A model is described which has been developed in the Netherlands to assess the performance of motorways and other high density routes. The model gives an overall assessment of the traffic delays which result from a capacity constraint. Performance chracteristics for different types of road are obtained from calculations relating to congestion formation. The degree of overloading can be expressed as the extent of the congestion which occurs and a quantitive impression of experienced delays can be obtained. These results are very useful for analysing present, planned or expected road traffic situations, for example in the process of the dimensioning of road sections and the timing of infrastructural projects.