Route optimization for solid waste collection: Onitsha (Nigeria) case study

Abstract

Routing of solid waste collection vehicles in developing countries poses a challenging task. New decision procedure for solid waste collection problem was introduced in this study. The problem objective was to minimize the overall cost, which was essentially based on the distance travelled by vehicle. The study proposed heuristic method to generate feasible solution to an extended Capacitated Arc Routing Problem (CARP) on undirected network, inspired by the refuse collection problems in Nigeria. The heuristic procedure consists of route first, cluster second method. The computational experience with the heuristic in Onitsha was presented. The technique was compared with the existing schedule with respect to cost, time and distance travelled. The adoption of the proposed heuristic in Onitsha resulted in reduction of the number of existing vehicles, a 22.86% saving in refuse collection cost and 16.31% reduction in vehicle distance travelled per day. The result revealed a good performance of the proposed heuristic method, which would be useful in vehicle scheduling. @ JASEM Solid waste collection is one of the most difficult operational problems faced by most cities in Nigeria. In most Nigerian cities, solid waste collections are done in an adhoc manner, which contributes to high solid waste collection cost. Solid waste collection vehicles are assigned to zones without any serious demand analysis, route construction being left to the drivers. Every time the vehicle is filled up, it heads to the disposal site to unload and then returns to the zones. This method contributes to high solid waste collection cost. This research stems from the need to address the solid waste collection truck routing problem for urban areas. Emphasis is placed on minimizing the cost of solid waste collection through collection route optimisation since nearly 77-95% of the solid waste budget is spent on collection and haulage in developing cities (Ogwueleka, 2003; Agunwamba et al, 1998).