An Approach to Coastal Railway Line Evacuation under a Tsunami Warning

Abstract

The analysis of transport network reliability under a natural disaster warning (e.g., impending tsunami) is a complex task, in part, due to the uncertainty of the time of the event occurrence at different locations. Different magnitudes and epicenters of earthquakes, as well as ocean bathymetry, will cause tsunami waves to have different arrival times and wave heights at different locations of a network. In this study, the southern coastal railway line in Sri Lanka, which is part single track and part double track, is analyzed to plan for the operation of trains under a tsunami warning. The confusion and concern that will prevail among passengers is taken into account. The poor communication and signal systems in place are also considered. Planning guidelines are proposed to improve communication and to select safe stations under various tsunami scenarios. If safe stations are not available, trains are directed to stations from which evacuation is possible to a safe location. A simple procedure and associated computer program for assigning trains to safe or evacuation stations are presented. Lessons for other coastal railways are drawn where possible.