Trip time model for municipal solid waste collection applicable to developing countries

Abstract

Municipal authorities in developing countries are faced with how to effectively and efficiently collect solid wastes from service points to disposal sites. Options for economy of time and improvement in the efficiency of collection operation can best be evaluated by conducting a time and motion study on an existing system. This study presents the development of a simulation model that calculates the time required to accomplish a solid waste collection trip. In order to determine a collection trip time, the collection operation was separated into units and the time required to perform each of these unit operations was simulated from field data. Results from the studied collection vehicle showed that the average pickup time was 1.68 minutes/trip, the average drop-down rate was 1.8 minutes/trip, and the average at-site time was 1.38 minutes/trip. The average time spent at intersections and turns was approximately 0.38 minutes and 0.18 minutes respectively. The haul time to the disposal site represented 0.034 of the travel distance to the disposal site, while the haul time from the disposal site represented 0.030 of the travel distance from the disposal site. When the model was applied to municipal solid waste collection in Ilorin, Nigeria, the estimated trip times were approximately 84% of the observed trip times. The estimated trip times by the model can find practical application as a decision support tool for municipal solid waste managers in areas of trip assignments, route design, logistics management and costs and emission reduction strategies.

Keywords:

• collection
• developing country
• hauled container
• solid waste
• trip time

Acknowledgements

The authors appreciate the assistance rendered by KWMC staff in obtaining field data. We also thank the US Department of State, sponsor of the Fulbright Foreign Student Program.