A literature review of the state of the art of sustainable waste collection and vehicle routing problem.

Over the past decades, the amount of waste has dramatically increased worldwide due to rapid population growth and urbanization. Inefficient waste collection and transportation, known as the waste collection vehicle routing problem (WCVRP), negatively impacts economic, environmental, and social dimensions. This issue has drawn considerable attention from local and national governments. There is an urgent need for sustainable practices in waste collection and transportation. This paper conducts an exhaustive literature review on the WCVRP. The review covers various aspects, including waste types, common model characteristics, objective functions, solution methods, datasets and case studies. The analysis indicates a need for further research on underrepresented waste types, such as medical waste (MW). It also stresses the importance of incorporating more model characteristics to better capture the complexities of real-world scenarios. Moreover, there is a lack of multiple objectives optimization models that concurrently address economic, environmental, and social dimensions, in line with sustainable development goals. Additionally, there is insufficient research on hybrid algorithms, especially regarding their application to uncertainty management and advanced techniques. Finally, the use of hybrid testing is restricted, highlighting the need for diverse tests to validate solution methods under various real-world conditions. This study outlines a roadmap for decision-makers in the WCVRP domain, offering opportunities for the evolution of more efficient, adaptable, and sustainable waste collection and transportation systems.: The discussion of WCVRP is an urgent global concern in waste management that requires immediate attention. Through a multi-dimensional evaluation of the research papers, this review paper provides recommendations for future research and practice in WCVRP. Initially, while urban solid waste has received significant attention, other categories remain insufficiently examined. Future research should focus on efficient collection and transportation strategies for these types. Then, although common characteristics are well-explored, this review emphasizes the need for further investigation into lesser-studied characteristics and vehicle types in WCVRP models. Next, current models predominantly prioritize cost and public health exposure risk minimization. There is a necessity for more holistic approaches that incorporate multiple objectives, particularly those crucial for achieving sustainable development goals. Moreover, hybrid algorithms have emerged as efficient solutions, yet advanced technologies coupled with uncertainty management strategies remain underutilized, presenting significant potential to address the evolving complexities of WCVRP. Finally, the study highlights the importance of datasets and case studies in validating WCVRP models. Hybrid tests enable researchers to comprehensively evaluate WCVRP solutions, providing insight into their performance under various conditions. In conclusion, these implications offer a roadmap for advancing WCVRP research and guiding practical strategies to contribute to the development of more efficient, adaptable, and sustainable waste collection and transportation systems.