Garbage collection is a topic for sustainable cities that are moving from picking up on individual houses to pick up garbage stored on containers. Minimizing trucks on the street, minimizing the travel times, while maximizing the number of containers that are picked up are desirable of the routes planned. This kind of problems have different types of constraints, for example, capacity constraints: limited number of trucks and each of different capacity. Some are time constraints, for example, a set of driver might have the morning shift, while some others work the night shift. Some constraints are topology based: a truck can not make a U-turn or an acute turn. This presentation you will learn the concepts behind this kind of optimization problems and how FOSS4G can facilitate finding a solution.