# Application of the Clark-Wright Method to Improve the Sustainability of the Logistic Chain
## 7 Conclusions  
The goal of this study was to improve material flows in the selected region, focusing on more efficient municipal waste collection through an appropriate optimization method. Municipal waste forms a significant part of material flows for any company, making its optimization critical for both financial efficiency and environmental sustainability. The Clark-Wright method was chosen for route optimization, implemented using a simple algorithm due to the complexity of the data.  
The optimization resulted in new municipal waste collection routes for the entire region, including one central city and 100 surrounding municipalities. The proposed routes reduced the total number by 20 compared to the current setup, leading to a significant decrease in overall route length. By adopting this solution, the company can achieve substantial fuel savings and reduce the number of vehicles needed by four, cutting down on maintenance and operational costs.  
While the optimization yielded positive outcomes, there are some challenges. The introduction of new routes will require time for crews to adjust and learn the new navigation, temporarily reducing collection efficiency. In Zilina, 11 routes were designed to serve 245 of 303 collection points, while in the surrounding area, 39 routes were consolidated into 20. The original weekly travel distance of 4896 km was reduced to 2447 km, saving 2449 km and 1469.4 liters of fuel annually.  
The new routing also saves 20 routes overall, freeing up four vehicles per day. The company could earn up to EUR 580,000 from selling surplus vehicles (with superstructures valued at EUR 100,000 for 7 m\({}^{3}\) and EUR 160,000 for 16 m\({}^{3}\)). In addition to cost savings, optimization brings long-term environmental benefits, such as reducing greenhouse gas emissions and lowering the company's environmental footprint by using resources more efficiently.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app14219908/s1](https://www.mdpi.com/article/10.3390/app14219908/s1)]([https://www.mdpi.com/article/10.3390/app14219908/s1](https://www.mdpi.com/article/10.3390/app14219908/s1)), Figure S1: Proposal of new routes in the city of Zilina: ZA4, ZA5, ZA6; Figure S2: Proposal of new routes in the city of Zilina: ZA10, ZA11; Figure S4: Proposal of new routes in around the city of Zilina: K1, K2, K3, K4; Figure S5: Proposal of new routes in around the city of Zilina: K5, K6, K7, K8; Figure S6: Proposal of new routes in around the city of Zilina: K12, K13, K14; Figure S8: Proposal of new routes in around the city of Zilina: O1, O2, O3, O4; Figure S9: Proposal of new routes in around the city of Zilina: O5, O6, O7, O8; Figure S10: Proposal of new routes in around the city of Zilina: O1, O14, O15, O16; Figure S12: Proposal of new routes in around the city of Zilina: O17, O18, O19, O20.  
Conceptualization, Z.B. and A.P.; methodology, J.M., Z.B. and A.P.; validation, J.M. and Z.B. formal analysis, Z.B.; investigation, J.M.; resources, Z.B. and A.P.; data curation, Z.B. and A.P.; writing--original draft preparation, Z.B. and A.P.; writing--review and editing, Z.B. and A.P.; visualization, Z.B., A.P. and J.M.; supervision, J.M. and Z.B.; funding acquisition, J.M. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
Data Availability Statement: Data is contained within the article and Supplementary Materials.  
The paper is supported by the VEGA Agency by Project 1/0485/24, \"Increasing the efficiency and sustainability of rail and water transport in the context of environmental impacts,\" which is being carried out at the Faculty of Operation and Economics of Transport and Communications, University of Zilina.  
The authors declare no conflict of interest.