application of a route expansion algorithm for transit routes design in grid networks

establishing a network of transit routes with satisfactory demand coverage is one of the main goals of transitagencies in moving towards a sustainable urban development. a primary concern in obtaining such anetwork is reducing operational costs. this paper deals with the problem of minimizing construction costsin a grid transportation network while satisfying a certain level of demand coverage. an algorithm isproposed following the general idea of “constructive algorithms” in related literature. the proposedalgorithm, in an iterative approach, selects an origin-destination with maximum demand, generates a basicshortest-path route, and attempts to improve it through a route expansion process. the paper reports thescenarios and further details of the algorithm considered for expanding a transit route in a grid network. arandom 6×10 grid network is applied to report the results. the results support that application of theproposed algorithm notably reduces the operational costs for various amounts of demand coverage.