Cyclic flows, Markov process and stochastic traffic assignment

Dial’s stochastic assignment algorithm restricts the assignment path set of ‘efficient path’. As a result, it sometimes produces the unrealistic flow pattern that no flow is loaded on some paths where many vehicles are running in reality. To remove the drawback of Dial’s algorithm, this paper presents the LOGIT type assignment that does not restrict the assignment paths. The paper first shows the theoretical relation between the proposed model and Sasaki’s assignment model through Markov process. This analysis makes it clear that the proposed assignment model can be calculated by some matrix operations. Next, it proposes an efficient algorithm that does not require the matrix operation nor path enumeration over a network. The algorithm solves an equivalent program based on the entropy decomposition derived from the Markov property of LOGIT model. Finally, it is shown that the proposed approach can be easily extended to the flow dependent case (i.e. stochastic equilibrium assignment).