Introducing heterogeneous users and vehicles into models and algorithms for the dial-a-ride problem

Variable Neighborhood Search Algorithms for the multi-depot dial-a-ride problem with heterogeneous vehicles and users

In this work, a study on Variable Neighborhood Search algorithms for multi-depot dial-a-ride problems is presented. In dial-a-ride problems patients need to be transported from pre-specified pickup locations to pre-specified delivery locations, under different considerations. The addressed problem presents several constraints and features, such as heterogeneous vehicles, distributed in differen...

Models and Algorithms for the Heterogeneous Dial-a-Ride Problem with Driver Related Constraints

This paper introduces models and algorithms for a dial-a-ride problem arising in the transportation of patients by non-profit organizations such as the Austrian Red Cross. This problem is characterized by the presence of heterogeneous vehicles and patients. In our problem, two types of vehicles are used, each providing a different capacity for four different modes of transportation. Patients ma...

Solving the Dial-a-Ride problem using genetic algorithms

The Dial-A-Ride Problem with Transfers

The Dial–A–Ride Problem with Transfers (DARPT) consists in defining a set of routes that satisfy transportation requests of users between a set of pickup points and a set of delivery points, in the presence of ride time constraints. Users may change vehicles during their trip. This change of vehicle, called a transfer, is made at specific locations called transfer points. Solving the DARPT invo...

The Integrated Dial-a-Ride Problem

In this paper we present a formulation of the Integrated Dial-a-Ride Problem (IDARP). This problem is to schedule dial-a-ride requests, where some part of each journey may be carried out by a fixed route service. The IDARP is a generalization of the Dial-a-Ride Problem. An arc-based formulation is proposed, and it is shown how the model can be made easier to solve by arc elimination, variable s...