Location problem for ambulances using multi-speed traffic network data

We consider location problems of ambulances. For the problems, we construct a traffic road network. The network contains two types of roads. They are major streets and the other roads. We assume that the speeds of ambulances are different in these two types of roads. We obtain the speeds by an iterative method. Using the network, we give a framework for evaluating ambulance systems by the continuous-time Markov chain method in the meaning of expected response time. We introduce two computational experiments for the ambulance system of Seto city. The first is a comparison with the results of our previous research. We obtain different optimal locations. This is because of using the traffic network. The second is a variation of our previous research. Locations of 4-medians are added to the candidates of the optimal locations. By comparing to the median problem, we discuss the effect of stochastic features in ambulance systems.