Methods for improving macro- and micro-routing problems of municipal solid waste: a literature review

The trend towards urbanization increases the challenges relating to collection and transportation of municipal solid waste (MSW), since the efficiency of waste management systems is affected by the optimality of these operations. The aim of this study is to develop a comprehensive literature review on methods for improving the technical, economic and environmental optimization of MSW collection and transportation systems, thereby exploring various issues addressed and the range of analytical approaches adopted for representing and solving waste collection and transportation problems. Three basic methods, including mathematical models, geographical information systems (GIS), and multi-criteria decision analysis (MCDA), are widely adopted thus addressing the various aspects of MSW management. In addition, gaps requiring future research were highlighted regarding the development of flexible models capable of managing complex systems, optimizing routes and site selection as well as focusing on dynamic optimization and real-time adjustments to manage variations in MSW production and operational conditions.