Enhancing resilience of transportation systems in case of disasters

The study was set out to explore the ways to increase resilience in a complex city system against disasters by focusing on the transportation system. The study seeks also to know the interaction pattern among structural, organizational, tactical, and public layers. Thus, the researcher conducted surveys in London and Istanbul to understand how the outcome of this interaction affects the transportation system. Organizational part includes upper level decision makers, tactical part includes the personnel in the field, - which could be the staff of transportation system and municipalities - and public part which are lay people. The study started with the problem definition that indicates the gap between the plans/blueprints as planned and the actual situation in the field when an incident occurs. This gap is a result of consideration failures about the interdependency of components in the system, secondary effects in hazard maps and social structure. These three issues are considered as the main reasons of the problem. The case study analyses and surveys showed that deeper problems, such as too much confidence in current operational and technological tools, lack of experience and misunderstanding of disaster situations derive from failure in considering interdependencies. The most important lesson from the study is that, a disaster risk/emergency management system that is constructed by rules and regulations may be technically correct. However, failures or incidents during an emergency are emergent phenomena. That kind of failures and reactions of the system, which includes both physical and social components, are hard to predict. In addition, outcome of actions, which are defined in the plan by regulations, could be different than anticipated due to constantly changing environment during disasters. In such a situation, new decisions, which are not defined in the plan, have to be taken with limited knowledge of the current situation. Failures occur when people insist on applying the written plans on fluctuating circumstances instead of re-organizing strategies and priorities. During crisis situations, flexible systems could be better than too much order in terms of resilience.