Route subnetwork generation is useful in modeling disaster emergency response operation problems such as evacuation, aid distribution, and personnel scheduling. Through this paper, we propose an end-to-end approach of generating a subnetwork based on a list of points of interest (villages, shelters, depots, etc) and publicly available data using a combination of opensource tools. Our final product is an opensource software published in a public code repository. We also present some experiments for three emergency response operations in Indonesia: the Yogyakarta earthquake (2020), Jakarta flood (2013), and Lombok earthquake (2018). Subnetwork generation with a muticore CPU was able to produce an average speedup of 1.67 times for the three disaster locations. For further research, the use of the Graphics Processing Unit (GPU) can be considered to accelerate the subnetwork generation process.