Study of the Dynamic Location of Emergency Rescue Facilities for Urban Bus Considering Rescue Urgency

Based on the analysis of deficiency of existing urban bus rescue facilities layout and characteristics of bus rescue demand, two kinds of emergency rescue facilities with different functions are designed. By considering the urgency of the rescue demand, an impedance function considering different traffic volume situations is constructed to calculate travel time. A dynamic multi-objective coverage model with objectives of maximizing covered demand, minimizing average rescue time and minimizing construction cost is built in several periods of time. The genetic algorithm is adopted to solve the problem. Taking Dazhou city of Sichuan Province as an example, the application of the method and the solution process are described. The results show that under the condition of meeting the minimum coverage, the optimal solution of the dynamic multi-objective coverage model is superior to the maximum covering model and the set covering model in terms of average rescue time and construction cost. The study has high practical value and could provide a reference for location selection of emergency rescue points when considering time-varying demand and different objectives.