Two-stage Combined Location Model of Railway Emergency Service Facility

Based on the analyses of the emergency demand point with interval characteristics, the traditional one-stage location model is improved and a two-stage model considering both the emergency service fairness and response time is proposed for the location problem of railway emergency service facility under the situation when the candidate points are unknown and the number of facility needs to be built. The validity of the model and algorithm is verified by case study. For the candidate points are unknown and facility number is known, the emergency service radius is reduced by 21.7% , and the difference of emergency service level is decreased by 35.8%, which improved the emergency service level of the whole system. The two-stage combined location model proposed in this paper is not only applicable to the location problems of railway emergency service facility of local area, but also suitable for those of nationwide. In the meantime, the model is also suitable for the location problems with unknown candidate points and given construction location numbers, as well as the multi-objective optimization ones with multiple alternatives.