Transportation

Integrating Order-to-Delivery Time Sensitivity in E-Commerce Middle-Mile Consolidation Network Design

  • Lacy M. Greening
  • Mathieu Dahan
  • Alan L. Erera
    • Categories Production and Logistics, Supply Chain Management, Transportation Tags , , ,

    This paper proposes an approach that leverages data on customer purchasing sensitivity to quoted order-to-delivery times (ODTs) when designing middle-mile consolidation networks to maximize the profit of e-commerce retailers. Our approach integrates quoted ODT-dependent sales volume predictions into a new mixed-integer program (MIP) that simultaneously determines ODT quotes and a consolidation plan, characterized by the … Read more

    The Vehicle Routing Problem with Access Restrictions

  • Munise Kubra Sahin
    • Categories Applications - OR and Management Sciences, Production and Logistics, Transportation Tags , , , ,

    To mitigate the negative effect of freight vehicles on urban areas, many cities have implemented road accessibility restrictions, including limited traffic zones, which restrict access to specific areas during certain times of the day. Implementing these zones creates a trade-off between the delivery cost and time, even under the assumption of equal traversal time and … Read more

    A new upper bound of the Euclidean TSP constant

  • Julien Yu
  • John Carlsson
    • Categories Data Science Applications, Transportation Tags , ,

    Let X1, X2, . . . , Xn be n independent and uniformly distributed random points in a compact region R ⊂ R2 of area 1. Let TSP(X1, . . . , Xn) denote the length of the optimal Euclidean traveling salesman tour that traverses all these points. The classical Beardwood-Halton-Hammersley theorem proves the existence … Read more

    Fair stochastic vehicle routing with partial deliveries

  • Natasja Sluijk
  • Walter Rei
  • Joris Kinable
  • Michel Gendreau
  • Tom Van Woensel
    • Categories Branch and Cut Algorithms, Stochastic Programming, Transportation Tags , , ,

    A common assumption in the models for the vehicle routing problem with stochastic demands is that all demands must be satisfied. This is achieved by including recourse actions in two-stage stochastic programming formulations or by ensuring with a high probability that all demand fits within the vehicle capacity (chance-constrained formulations). In this work, we relax … Read more

    Optimal Planning for the Electrification of Bus Fleets in Public Transit Systems

  • Filipe Cabral
  • Xu Andy Sun
    • Categories Applications - OR and Management Sciences, Integer Programming, Transportation Tags , , ,

    Electric vehicles (EV) pave a promising way towards low-carbon transportation, but the transition to all EV fleets creates new challenges for the public transportation sector. Despite increasing adoption of electric buses, the main challenges presented by the battery electric bus technology include the lack of charging facilities, the reduced operating capacity per battery charge compared … Read more

    The Online Shortest Path Problem: Learning Travel Times Using A Multi-Armed Bandit Framework

  • Tomas Lagos
  • Ramon Auad
  • Felipe Lagos
    • Categories Applications - OR and Management Sciences, Data Science Algorithms, Transportation Tags , , , , ,

    In the age of e-commerce, many logistic companies must operate in large road networks without accurate knowledge of travel times for their specific fleet of vehicles. Moreover, millions of dollars are spent on routing services that do not accurately capture the specific characteristics of the companies’ drivers and the types of vehicles they must use. … Read more

    A Column Generation Approach for the Lexicographic Optimization of Intra-Hospital Transports

  • Andreas Bärmann
  • Alexander Martin
  • Alexander Müller
  • Dieter Weninger
    • Categories Integer Programming, Multi-Criteria Optimization, Transportation Tags , , , , ,

    Over the last fewyears, the efficient design of processes in hospitals and medical facilities has received more and more attention, particularly when the improvement of the processes is aimed at relieving theworkload of medical staff. To this end,we have developed a method to determine optimal allocations of intra-hospital transports to hospital transport employees. When optimizing … Read more

    Toward Efficient Transportation Electrification of Heavy-Duty Trucks: Joint Scheduling of Truck Routing and Charging

  • Mikhail Bragin
    • Categories (Mixed) Integer Linear Programming, Combinatorial Optimization, Transportation Tags

    The timely transportation of goods to customers is an essential component of economic activities. However, heavy-duty diesel trucks that deliver goods contribute significantly to greenhouse gas emissions within many large metropolitan areas, including Los Angeles, New York, and San Francisco. To facilitate freight electrification, this paper proposes joint routing and charging (JRC) scheduling for electric … Read more

    Solving Unsplittable Network Flow Problems with Decision Diagrams

  • Hosseinali Salemi
  • Danial Davarnia
    • Categories (Mixed) Integer Linear Programming, Network Optimization, Transportation Tags , , ,

    In unsplittable network flow problems, certain nodes must satisfy a combinatorial requirement that the incoming arc flows cannot be split or merged when routed through outgoing arcs. This so-called “no-split no-merge” requirement arises in unit train scheduling where train consists should remain intact at stations that lack necessary equipment and manpower to attach/detach them. Solving … Read more

    Decremental State-Space Relaxations for the Basic Traveling Salesman Problem with a Drone

  • Marcos Blufstein
  • Gonzalo Lera-Romero
  • Francisco J. Soulignac
    • Categories Dynamic Programming, Transportation Tags , , , , ,

    Truck-and-drone routing problems have become an important topic of research in the last decade due to their applications for last-mile deliveries. Despite the large number of publications in this area, the most efficient exact algorithms designed thus far struggle to solve the benchmark instances with 39 or more customers. This fact is true even for … Read more