title: Variable neighborhood search to solve the vehicle routing problem for hazardous materials transportation.
abstract: This work focuses on the Heterogeneous Fleet Vehicle Routing problem (HFVRP) in the context of hazardous materials (HazMat) transportation. The objective is to determine a set of routes that minimizes the total expected routing risk. This is a nonlinear function, and it depends on the vehicle load and the population exposed when an incident occurs. Thus, a piecewise linear approximation is used to estimate it. For solving the problem, a variant of the Variable Neighborhood Search (VNS) algorithm is employed. To improve its performance, a post-optimization procedure is implemented via a Set Partitioning (SP) problem. The SP is solved on a pool of routes obtained from executions of the local search procedure embedded on the VNS. The algorithm is tested on two sets of HFVRP instances based on literature with up to 100 nodes, these instances are modified to include vehicle and arc risk parameters. The results are competitive in terms of computational efficiency and quality attested by a comparison with Mixed Integer Linear Programming (MILP) previously proposed.
authors.affiliation: ICD-LOSI, Universitéde Technologie de Troyes, Troyes Cedex 10004, France; System and Industrial Engineering Department, Universidad Nacional de Colombia, Bogotá, Colombia. Electronic address: gabula@unal.edu.co.
authors.forename: Gustavo Alfredo
authors.initials: GA
authors.lastname: Bula
authors.affiliation: ICD-LOSI, Universitéde Technologie de Troyes, Troyes Cedex 10004, France. Electronic address: caroline.prodhon@utt.fr.
authors.forename: Caroline
authors.initials: C
authors.lastname: Prodhon
authors.affiliation: System and Industrial Engineering Department, Universidad Nacional de Colombia, Bogotá, Colombia. Electronic address: fagonzalezo@unal.edu.co.
authors.forename: Fabio Augusto
authors.initials: FA
authors.lastname: Gonzalez
authors.affiliation: ICD-LOSI, Universitéde Technologie de Troyes, Troyes Cedex 10004, France. Electronic address: murat.afsar@utt.fr.
authors.forename: H Murat
authors.initials: HM
authors.lastname: Afsar
authors.affiliation: School of Management, Universidad de los Andes, Bogotá, Colombia. Electronic address: nvelasco@uniandes.edu.co.
authors.forename: Nubia
authors.initials: N
authors.lastname: Velasco
keywords: Heterogeneous vehicle routing problem; Transportation risk assessment; Variable neighborhood search