School commuting is crucial in modern societies, considering its impact on the travel choices for parents, and the travel behavior of the young generation. It is important to use sustainable transport modes for school commuting, in order to reduce traffic and engage children in active travelling. The Walk to School Bus (WSB) has been recognised as means to achieve this goal. The WSB involves a group of adults walking on defined routes with pre-determined stop points for picking-up the children and walk them to the school destination. This problem has recently attracted the research community.
The WSB is a difficult routing problem with multiple conflicting objectives. It compromises of several sub-problems that are also hard such as the route design and leaders rostering and scheduling. This makes it an interesting real-world problem for optimisation research. Our goal is to design an optimisation tool to find the optimal routes set based on multi criteria on targeted areas for applying the WSB.
Our focus on this study will be on the route design aspect and allocating potential stop points for picking up/dropping children. We develop a mathematical model that aims to find the optimal walking routes based on the following objectives: travel time, pollution dose, and walkability, where we define the walkability as the factors that affect the quality and comfort of the walking experience. Our work is pioneer in proposing an in-depth description for the WSB mathematically, defining its constraints, and developing mathematical formulations for modelling a realistic version of a WSB.
Our preliminary results are given based on road network data from the city of Bradford in UK. We convert the road network to a walking network on which the routes are defined. We prove that our implementation is general and can adapt to any case of city or school.