I. Introduction
The School Bus Routing Problem (SBRP) [1]–[5] is a classical combinatorial optimization problem which, given a set of roads, schools, students, vehicles and garages, consists of generating an efficient schedule for a fleet of school buses. Each bus picks up students from various bus stops and delivers them to their designated schools while satisfying various constraints such as the maximum capacity of a bus, the maximum riding time of a student in a bus and the time window of a school. According to [2] the SBRP can be divided into five sub-problems: Data Preparation; Bus Stop Selection;Routes Generation; School Bell Time Adjustment and Route Scheduling. As far as we are concerned, only Desrosiers et al. [2], [6] address all five steps of the SBRP. Normally, the research works deal with the Route Generation and the Route Scheduling steps.