In this paper we introduce some improvements on an approach that we described elsewherefor solving a modification of the well-known extended rapid transit network designproblem. Firstly, we propose an integer programming model for selecting the stations to beconstructed and the links between them, in such a way that a connected rapid transitnetwork is obtained. Secondly, we consider a linear 0-1 programming model for determininga route of minimum length in the rapid transit network between certain pairs of locations,and present a greedy heuristic procedure which attempts to minimize an estimation of thetotal number of transfers that should be made by the users to arrive at theirdestinations. We also report several computational experiments that show that thisprocedure can significantly reduce the estimated total number of transfers required forthe solutions obtained using our previous approach.
