A Constraint Model for Vehicle Routing and Driver Scheduling

In this research, we study a transportation problem which is concerned with vehicle routing and driver scheduling for a bus station. The problem requires drivers to provide pick-up and delivery services to customers. Its solution involves planning itineraries for buses and establishing working schedule for drivers, subject to vehicle capacity limitation and time constraints. The objective is to optimally schedule the fleet of vehicles for customer demand so as to reduce costs. This paper presents a complete constraint model for solving the problem. For vehicle routing, a permutation constraint is used to impose a total order for visiting all customer locations, which provides a global planning over all routes. For driver scheduling, set partitioning constraints are used for assigning drivers and vehicles to requests.