The impact of public drop-off boxes and autonomous delivery robots in last-mile delivery

Abstract

The growing concern over emissions from last-mile logistics is motivating the development of innovative delivery models aimed at reducing environmental impact and traffic congestion. To this end, we propose a last-mile delivery scheme based on both public drop-off boxes and autonomous delivery robots. Unlike current practices, we assume that parcels are primarily delivered by a fleet of traditional vehicles to a number of drop-off boxes owned by the municipalities and shared by several logistics providers. Then, citizens must autonomously reach the drop-off point to retrieve their parcels. An exception is made for a small group of customers (like, for instance, elderly or disabled people) whose parcels are loaded on autonomous delivery robots and home-delivered, starting from the drop-off points. To tackle this problem, we devise tailored destroy-and-repair operators to be embedded into a neighborhood-search framework. We then conduct an extensive computational study on a set of realistic instances based on the urban area of Rome (Italy), aimed at assessing the benefits of the proposed last-mile delivery infrastructure, compared to traditional distribution methods. Additionally, we evaluate the environmental and economic advantages of using autonomous delivery robots and drop-off points.