Transport infrastructure interdependency: Metro's failure propagation in the road transport system in Mexico City

On Friday, 3 March 2017, at about 18:19 h, a metro track failed, prompting about 50% of Mexico City's metro line-C to a halt. The track failure occurred at a peak hour when tens of thousands of commuters were heading to their homes. Given the interdependency among the modes of transportation in the capital city, the incident caused heavy disruption; it is believed that about 45,000 commuters were affected. A systemic safety management system ('SSMS') model has been used for the analysis. The results showed that: a) the model demonstrated its potential to the analysis of the transport system interdependency; it has been found that failure propagates vertically and horizontally; b) the model highlighted that failure propagation has to do with a coordination function; c) in relation to the case study, it has been found that the actions taken by the decision-makers during the emergency were less than adequate; d) the commuters traveling patterns should be considered when designing emergency plans; and, e) more generally, there is a need for the creation of a system to manage critical infrastructure protection in the context of Mexico. It is hoped that by conducting such analyses, we may gain a better understanding of the complexity of cities.