Exact and heuristic methods for public transit circulator design.

This work presents a new mixed integer model for a single-route circulator design problem. An exact method that performs well in practice on medium-sized networks is presented that utilizes 1-trees as lower bounds and a stopping criterion relevant in non-Steiner networks. Proof of the correctness of this stopping criterion is provided. A heuristic method is presentedfor large networks. Both methods are tested on sample networks along a commuter rail line in Austin, TX in several problem variations and results of these tests presented. The practical and theoretical implications of this work are outlined. (A) Reprinted with permission from Elsevier.