Tree-building with complex cost structures — A new algorithm for incorporation into transport demand models

This paper highlights some of the difficulties involved in the implementation of complex cost structures in the tree-building section of a transport demand model. The conventional tree-building algorithm is briefly described and is seen to be inadequate for the present purpose. A new algorithm is then presented which is able to implement complex cost structures properly. An example is given of the application of this algorithm to the building of tree in a public transport network. The performance of a computer program incorporating the new alrogrithm is evaluated against alternative methods of implementing complex cost structures. Some mention is then made of the vast range of potential uses for the new algorithm in the field of transport modelling and simulation.