Considering the Traffic Congestion Impact on Emergency Vehicle Planning in the Earthquake Response Phase

Traffic congestion during the earthquake response phase could significantly affect relief emergency logistics planning and endangers injured people’s lives. Given this significant impact, this study develops a mathematical formulation to employ the BPR function and capture the traffic congestion impact on emergency vehicle planning for casualty transportation. The problem under investigation is formulated as a mixed integer non-linear programming (MINLP) that comprises multi-objective functions and considers different modes of transportation for casualties. The developed formulation is then linearized through a piecewise linear function technique. Subsequently, we employ the lexicographic and weighted sum techniques to develop a hybrid solution algorithm for solving the proposed linear formulation. Finally, the developed formulation and solution algorithm are applied in a numerical case to investigate the impact of traffic congestion. The result reveals the significant effects of traffic congestion on vehicle delays, choosing emergency vehicle routing, allocating emergency vehicles to the routes and hospitals, and assigning injured people to the emergency vehicles and the hospitals. This analysis also exhibits that applying the developed mechanism improves casualty transportation in the earthquake response.