1,310 research outputs found
Road-based goods transportation : a survey of real-world logistics applications from 2000 to 2015
The vehicle routing problem has been widely studied from a
technical point of view for more than 50 years. Many of its variants
are rooted in practical settings. This paper provides a survey of the
main real-life applications of road-based goods transportation over
the past 15 years. It reviews papers in the areas of oil, gas and fuel
transportation, retail, waste collection and management, mail and
package delivery and food distribution. Some perspectives on
future research and applications are discussed
Driver Routing and Scheduling with Synchronization Constraints
This paper investigates a novel type of driver routing and scheduling problem
motivated by a practical application in long-distance bus networks. A key
difference from other crew scheduling problems is that drivers can be exchanged
between buses en route. These exchanges may occur at arbitrary intermediate
stops such that our problem requires additional synchronization constraints. We
present a mathematical model for this problem that leverages a time-expanded
multi-digraph and derive bounds for the total number of required drivers.
Moreover, we develop a destructive-bound-enhanced matheuristic that converges
to provably optimal solutions and apply it to a real-world case study for
Flixbus, one of Europe's leading coach companies. We demonstrate that our
matheuristic outperforms a standalone MIP implementation in terms of solution
quality and computational time and improves current approaches used in practice
by up to 56%. Our solution approach provides feasible solutions for all
instances within seconds and solves instances with up to 390 locations and 70
requests optimally with an average computational time under 210 seconds. We
further study the impact of driver exchanges on personnel costs and show that
allowing for such exchanges leads to savings of up to 75%
A metaheuristic for crew scheduling in a pickup-and-delivery problem with time windows
A vehicle routing and crew scheduling problem (VRCSP) consists of
simultaneously planning the routes of a fleet of vehicles and scheduling the
crews, where the vehicle-crew correspondence is not fixed through time. This
allows a greater planning flexibility and a more efficient use of the fleet,
but in counterpart, a high synchronisation is demanded. In this work, we
present a VRCSP where pickup-and-delivery requests with time windows have to be
fulfilled over a given planning horizon by using trucks and drivers. Crews can
be composed of 1 or 2 drivers and any of them can be relieved in a given set of
locations. Moreover, they are allowed to travel among locations with
non-company shuttles, at an additional cost that is minimised. As our problem
considers distinct routes for trucks and drivers, we have an additional
flexibility not contemplated in other previous VRCSP given in the literature
where a crew is handled as an indivisible unit. We tackle this problem with a
two-stage sequential approach: a set of truck routes is computed in the first
stage and a set of driver routes consistent with the truck routes is obtained
in the second one. We design and evaluate the performance of a metaheuristic
based algorithm for the latter stage. Our algorithm is mainly a GRASP with a
perturbation procedure that allows reusing solutions already found in case the
search for new solutions becomes difficult. This procedure together with other
to repair infeasible solutions allow us to find high-quality solutions on
instances of 100 requests spread across 15 cities with a fleet of 12-32 trucks
(depending on the planning horizon) in less than an hour. We also conclude that
the possibility of carrying an additional driver leads to a decrease of the
cost of external shuttles by about 60% on average with respect to individual
crews and, in some cases, to remove this cost completely
A decomposition approach to the integrated vehicle-crew-rostering problem
The problem addressed in this paper is the integrated vehicle-crew-rostering problem (VCRP) aiming to define the schedules for the buses and the rosters for the drivers of a public transit company. The VCRP is described by a bi-objective mixed binary linear programming model with one objective function aggregating vehicle and crew scheduling costs and the other the rostering features. The VCRP is solved by a heuristic approach based on Benders decomposition where the master problem is partitioned into daily integrated vehicle-crew scheduling problems and the sub-problem is a rostering problem. Computational experience with data from a bus company in Lisbon shows the ability of the decomposition approach for producing a variety of potentially efficient solutions for the VCRP within low computing times
Planning of Truck Platoons: a Literature Review and Directions for Future Research
A truck platoon is a set of virtually linked trucks that drive closely behind one another using automated driving technology. Benefits of truck platooning include cost savings, reduced emissions, and more efficient utilization of road capacity. To fully reap these benefits in the initial phases requires careful planning of platoons based on trucks’ itineraries and time schedules. This paper provides a framework to classify various new transportation planning problems that arise in truck platooning, surveys relevant operations research models for these problems in the literature and identifies directions for future research
Implications of technological changes in vehicle routing interfaces for planners' constraint processing
International audienceThis study sought to assess the consequences of technological changes in vehicle routing interfaces for planners' constraint processing during route selection. We began by developing a model of domain constraints for the generic vehicle routing problem, in order to characterize planners' constraint processing and assess the visibility of constraints on different routing interfaces. An experiment featuring vehicle routing problems was then designed to test interfaces reflecting technological changes, including automation leading to simplified interfaces and the display of multiple routes computed by algorithms. Twelve participants who had worked for a small transport company for nine months were exposed to all these interfaces. Mental workload, performance and decision-making times were measured. Results revealed that automation decreases mental workload and decision times, attributable to the abridged (vs. unabridged) display of constraints on the interface. Results also showed that the perceptual (vs. analytical) display of routes greatly decreases decision times and enhances performances
Solving Public Transit Scheduling Problems
Operational planning within public transit companies has been extensively tackled but still remains a challenging area for operations research models and techniques. This phase of the planning process comprises vehicle scheduling, crew scheduling and rostering problems. In this paper, a new integer mathematical formulation to describe the integrated vehicle-crew-rostering problem is presented. The method proposed to solve this multi-objective problem is a sequential algorithm considered within a preemptive goal programming framework that starts from the solution of an integrated vehicle and crew scheduling problem and ends with the solution of a driver rostering problem. Feasible solutions for the vehicle and crew scheduling problem are obtained by combining a column generation scheme with a branch-and-bound method. These solutions are the input of the rostering problem, which is tackled through a mixed binary linear programming approach. An application to real data of a Portuguese bus company is reported and shows the importance of integrating the three scheduling problems
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