Location of Railway Emergency Rescue Spots Based on a Near-Full Covering Problem: From a Perspective of Diverse Scenarios

Abstract

The location of railway emergency rescue spots is facing diverse scenarios including the location of new facilities and optimization of existing layouts with limited or non-limited conditions. Generally there will be heavily redundant covering ability if all the edge demands on a network are fully covered. Here, we first proposed a near-full covering model to balance investment in the facility and the actual coverage rate, and successfully applied this model in the optimal location of railway emergency rescue spots under diverse scenarios. We also developed a feasible solution that can select an effective algorithm or a greedy algorithm based on the total consumed time. With the constraint of a fixed coverage rate threshold, a larger coverage radius may lead to fewer facilities and higher relative redundancy. Flexible designs of the important node set where all the elements must be selected and the exclusive node set where all the elements cannot be selected are carried out to construct several scenarios. The comparative analysis shows that the optimal solution is an obvious improvement on the existing emergency rescue spot layout in the real railway network. This study provides an alternative version of the edge covering problem, and shows a successful application in the location problem of railway rescue spots.