"Solid Waste Routing by Exploiting Ant Colony Optimization" is a new work which is influenced by the problem arising now a days by the solid waste generated in metro (big) cities. The waste generated on daily bases creates a lot of problem in environment. Solid Waste Management has evolved as a complex discipline in the last decades. One key subsystem of solid waste management is designing vehicle routes with all the realistic constraints. The basic problem consists of collecting garbage house by house and, therefore street by street. The management of urban solid waste is intrinsically complex, because it involves various relative factors, which are often in conflict. Moreover, given that this solution cannot be reduced easily to the optimization, a formal multi-criteria urban waste management approach is needed.