Evaluating passenger robustness in a rail transit network

The purpose of this paper is to provide passenger robustness measures for a rail transit network. A network is robust when it reacts well to disruptions on links or stations. In order to measure robustness, indexes relative to the overall travel time of a network when links fail are introduced for two different cases: without-bridging interruptions and with-bridging interruptions. In the first case, passengers either have to wait for the failure to be repaired or find an alternative route in the network, whereas in the second case a bus service between the affected stations is provided and only the failing link is disrupted. A computation of these indexes for the Madrid commuter system shows their applicability.