Investigation of Accessibility Formulations for Urban Freight Distribution using E-VRP

The objective of the paper is to gain insight onto which territorial characteristics of an urban area contribute in the determination of accessibility for freight distribution. This issue becomes relevant today because of the increasing use of electric vehicles with a limited driving range, the wide diffusion of realtime freight distribution in urban areas, which requires ITS applications to city logistics. Specifically, an Electric Vehicle Routing Problem (E-VRP) solving procedure is used to extend the traditional accessibility modelling to include the trip-chaining effects of distribution tours in the accessibility formulation. This work generalizes the impedance function based on direct trips, as it is typical in passenger mobility or long-haul freight distribution, to derive an impedance function that considers the complexity of the interactions between the transportation network and the activity system. To this goal, this paper introduces a new formulation of the incremental cost for legs of distribution tours, that better defines the impedance or cost of travel. A case study is presented and different formulations are proposed and applied, while the costs computed with the E-VRP algorithm are used to validate accessibility results.