The Truck-Porters Routing Problem

Abstract

This thesis introduces a new problem that arises when last-mile deliveries in urban areas are undertaken. It is named the truck-porters routing problem (TPRP) and is applicable when vehicle access to some customers is impossible. Some deliveries are therefore undertaken by porters who walk to some of the customers, while a truck is driven to deliver to the other ones. In the TPRP, a single truck and a limited number of identical porters are available at the depot. For the customers, some must be visited by the truck, some must be served by a porter, and the remainder can be visited either by the truck or by a porter. Porters are limited by the total weight of items that they can carry and by a total working time constraint. However, a porter can revisit the depot to collect further items for delivery. The TPRP problem consists of designing a set of minimum-cost routes, where each route starts and ends at the depot and satisfies capacity and travel time constraints.