A HEURISTIC MODEL FOR MUNICIPAL SOLID WASTE COLLECTION VEHICLE ROUTING

摘要

Appropriate vehicle routing is critical for collecting municipal solid waste (MSW) efficiently. Conventional empirical routing is not easily altered in response to rapidly changing waste management plans and generation. An enhanced model is proposed herein to solve a MSW collection routing problem involving a homogenous fleet. A minimum cost flow method is applied to pre-process the original collection network for vehicle flow balance. Collection of MSW along a street segment is transformed into a node expression. With this arc-node transformation and the property of trichotomy, the sub-tour problem can be practically resolved. A mixed-integer programming model is established for the transformed network. In addition to reducing the collection time, the model also considers the workload balance among vehicles and vehicle turning suitability. The proposal model has been applied to the eastern district of Hsinchu City, Taiwan. Results obtained from the case study demonstrate the effectiveness of the proposed model in reducing the collection time, deviation of workloads, inappropriate turns, and redundant routes.