Speeding up quickest-route assignments in CONTRAM with an heuristic algorithm

The CONTRAM traffic assignment program uses a variation of Dijkstra’s quickest-route algorithm for finding routes between particular origins and destinations. The run-time of CONTRAM is dominated by the large number of vehicle assignments which it has to perform, so the efficiency of the route algorithm is critical. This paper describes a practical heuristic method of improving the efficiency of the quickest-route assignment algorithm by using simple estimates of the travel times between all network nodes and each destination. Examples are given which show that the amount of computation can be reduced by as much as two-thirds.