Although hazardous materials (Hazmat) transportation plays an important role in the economy, it has always raised authorities’ concerns on the potential risks to humans and the environment. A Hazmat accident may impact serious damage to the people within the scope of the incident so in the areas where special relief centers do not exist, Hazmat accidents may be more severe. In the present research work, a mathematical model for locating the relief and rescue centers has been developed in which the network risk coverage is maximized. A procedure has been developed to determine the optimum sites for constructing special relief and rescue centers based on Hazmat transport risk. In order to validate the proposed model, an experimental intercity road network including 46 nodes and 126 two-way edges (252 edges) in the Iranian northern province of Guilan has been selected as the case study. The results revealed that solving locating problems in terms of risk coverage and distance coverage have different results on location, so local or national authorities who are dealing with Hazmat transport planning should be aware on attributes considered for locating rescue and relief centers.