Transportation Planning for Disasters: An Accessibility Approach

A methodology is developed in this paper for evaluating and enhancing the performance of urban transportation systems in the aftermath of a disaster. A performance measure is proposed for assessing overall and distributional impacts based on the concept of accessibility. The methodology is demonstrated with two case studies. The first focuses on passenger railroad disruption in the catastrophic 1995 Kobe earthquake in Japan. An accessibility measure is applied to evaluate the loss of transportation service and, in particular, its attendant spatial disparities. Alternative repair and restoration strategies are investigated and shown, in hindsight, to be preferable to the actual sequence of repairs. The second case study focuses on the potential loss of road and highway transportation in Seattle, WA, after a hypothetical earthquake. A refined accessibility measure is applied that accounts for postdisaster detouring and congestion. Again, this brings attention to spatial disparities in loss and the spatial implications of alternative restoration priorities. It further demonstrates that restoration strategies should be designed from a systems perspective. The limitations and broader applicability of the approach are discussed.