A lesson learned time and again from major urban earthquakes is that the management and operation of transportation facilities play significant roles in the overall earthquake preparedness, response, and recovery. The scope of this study is to extract lessons from the October 17, 1989 San Francisco earthquake in terms of the transportation needs encountered and actions taken. The data obtained will be integrated into a microcomputer-based decision tool with capabilities in graphical network editing and zooming, traffic control and diversion strategies, and mass transit resource management and operations. Similar studies following the 1985 Mexico City earthquake have led to the development of TEDSS, the Transportation Emergency Decision Support System. TEDSS fulfills a number of crucial transportation needs pertinent to Mexico City conditions. These include real-time network editing capabilities, emergency vehicle dispatch, and street clean-up prioritization. The recent San Francisco experience has shown intermediate needs such as route diversions, response to modified travel patterns, and changes in transit demand and routes to also be highly significant in recovery efforts and return to normalcy. These functions will be added to TEDSS making it more adaptable to the U.S. needs and conditions while other TEDSS functions unsuitable to U.S. conditions are deleted. In the course of modifying TEDSS, efficient data structures, graphics modules, heuristics algorithms, and a higher order programming language will be employed to increase the software speed and capacity to handle larger regional street networks.
