Optimal truck scheduling in a container terminal by using a Truck Appointment System

Truck congestion is one of the most critical problems that affect many port realities around the world. To alleviate the truck congestion problem in container terminals, several approaches have been proposed and implemented. One of them refers to Truck Appointment Systems (TASs), which are technological platforms aiming to coordinate truck flows at ports, by supporting the scheduling of truck arrivals and truck operations. In this paper an integer programming model is formulated to schedule the operations of trucks that have to pick up or deliver containers in a container terminal operating with a TAS. The mathematical model seeks to assign appointments to the different time slots composing the gate opening time, with the goal of optimizing terminal resources, guaranteeing a predefined service level to haulers (i.e. maximum turnaround times in the container terminal), while minimizing congestion inside the terminal. The validity of the proposed optimization approach is highlighted by an experimental campaign based on real data sets provided by some Italian and Mexican container terminals. The obtained results highlight that the proposed model is efficient in reducing waiting times of trucks, improving both the operation efficiency and the accuracy of resource allocation in container terminals. Particularly, it can be observed that the terminal vehicle capacity and the truck arrival pattern are the most significant factors that affect the total truck delay.