Multicopter Drone Mass Distribution Impacts on Viability, Performance, and Sustainability

This short communication highlights the value of drone mass and its distribution, a topic that despite its importance has received scant attention in the rapidly growing drone literature. In particular, the focus is on the impact of mass distribution on drone viability, performance, and sustainability

Drones for Commercial Last-Mile Deliveries: A Discussion of Logistical, Environmental, and Economic Trade-Offs

There are no studies that model the potential effectiveness of Unmanned Aerial Vehicles (UAVs) or drones to reduce CO2e lifecycle (including both utilization and vehicle phase) emissions when compared to conventional diesel vans, electric trucks, electric vans, and tricycles. This study presents a novel analysis of lifecycle UAV and ground commercial vehicles CO2e emissions

Analysis and Evaluation of Incentive Compatible Dynamic Mechanisms for Carrier Collaboration

This paper introduces a framework for carrier dynamic collaboration. In particular it proposes and analyzes dynamic collaborative mechanisms that are incentive compatible. The dynamic collaborative environment is characterized by a set of carriers that have a proprietary set of customers that generate a stream of random demands over time. The proposed collaborative mechanism is such that upon each demand arrival, each carrier has the incentive to submit the arrived shipment or service request to the collaborative mechanism. Intuition about the efficiency and workings of the collaborative mechanism is developed. A general framework to formulate and study collaborative frameworks among transportation carriers is proposed. A truckload pickup-and-delivery collaborative environment is simulated and results are analyzed

The Impacts of Congestion on Commercial Vehicle Tours Characteristics and Costs

Congestion is a common phenomenon in all major cities of the world. Increased travel time and uncertainty brought about by congestion impacts the efficiency of logistics operations. Recent studies indicate that a significant proportion of commercial vehicle kilometers traveled (VKT) and vehicle hours traveled (VHT) are generated by trip-chains or multi-stop tours. This paper presents research demonstrating the impact of congestion on multi-stop tours in urban areas. An analytical model, numerical experiments, and real-world tour data are used to understand the impact of congestion on tour characteristics, carriers? costs, VKT, and VHT. This research shows that travel time/distance between customer and depot is a crucial factor that exacerbates the negative impacts of congestion. Travel time variability is not as significant when the travel time between the depot and the customers is small in relation to the maximum tour duration and when the routes are not highly constrained. As congestion increases, the number of vehicles needed to complete the tour also increases. This is accompanied by an increase in the percentage of total driving time and the average distance travelled per customer. Congestion impacts on carriers? costs are also considerable since congestion not only increases carriers? operating costs but also affects carriers? cost structure. As congestion worsens the relative weight of labor costs ? wages and overtime ? escalates. This paper categorizes tours into three classes based on tour efficiency and the relative weight of time and distance related costs. These are intuitive and valuable tools to monitor congestion, represent real-world tour data, and classify tours in regards to their sensitivity to congestion

Modeling the Impact of Technological Changes on Urban Commercial Trips by Commercial Activity Routing Type

An array of noteworthy developments in logistics practice has taken place without an equivalent and comprehensive development in urban freight transportation modeling. Part of the problem is the lack of deep understanding of the workings of distribution processes in relation to the generation of truck traffic. In this paper it is emphasized the role and importance that distribution network size, and information and communication technology have on the truck traffic flows that materializes as the supply chain that flows over the public infrastructure. This paper develops the concept of commercial activity routing types that characterize the interplay between transportation demand requests and routing characteristics. This research contributes to the field proposing a novel and detailed characterization of truck flows in a supply chain context. Using well-known yet simple models and formulas from vehicle routing, operations research, and management science literature, we derive behavioral insights about distributors and carriers’ routing and order sizing decisions, as routing constraints and second order effects are important drivers of truck flows. The main contribution is to bring a new commercial activity-routing perspective and deeper level of operational decision-making analysis to cope with the intricacies of freight transportation modeling

Analysis of the Efficiency of Commercial Vehicle Tours: Data Collection, Methodological, and Policy Implications

The emphasis of this research is on the analysis of commercial vehicle tours. Tours are disaggregated by their routing constraints. The generation of Vehicle Kilometers Traveled (VKT) by tour type is analytically modeled and analyzed. The relative influence of the number of stops per tour, tour duration, and time window constraints on VKT is discussed using an analytical framework. Multistop tours are proven to generate more VKT than direct deliveries even for equal payloads. Intuition about the impacts of network changes and policy implications on VKT is derived. Implications for the calibration of trip generation and distribution models are discussed. It is proved that the percentage of empty trips has no correlation with the efficiency of the tours regarding VKT generation. The shape of Trip Length Distributions (TLD) is discussed. It is shown that the average trip length and the TLD shape are strongly dependent on the tour type, distance from the depot/distribution center to the service area, density of stops, and number of stops per tour. Implications for data collection needs are analyzed. Data and indicators that are needed to estimate and forecast truck VKT are proposed

Analysis and Evaluation of Incentive Compatible Dynamic Mechanisms for Carrier Collaboration

This paper introduces a framework for carrier dynamic collaboration. In particular it proposes and analyzes dynamic collaborative mechanisms that are incentive compatible. The dynamic collaborative environment is characterized by a set of carriers that have a proprietary set of customers that generate a stream of random demands over time. The proposed collaborative mechanism is such that upon each demand arrival, each carrier has the incentive to submit the arrived shipment or service request to the collaborative mechanism. Intuition about the efficiency and workings of the collaborative mechanism is developed. A general framework to formulate and study collaborative frameworks among transportation carriers is proposed. A truckload pickup-and-delivery collaborative environment is simulated and results are analyzed

Evaluation of Different Approaches for the Truckload Vehicle Routing Problem in a Competitive Environment

The principal focus of this research is to evaluate the effectiveness of different approaches for the vehicle routing problem in a competitive environment (VRPCE). This paper focuses on the study of the VRPCE in a marketplace with time-sensitive truckload pickup-and-delivery requests. In this paper, two carriers compete for service requests; each arriving service request triggers an auction where carriers compete with each other to win the right of servicing the load. This paper will show how the efficiency of routing and costing approaches in different market settings will depend on these carriers’ approaches. A simulation framework is used to evaluate different strategies. Some results and the overall simulation framework are also discusse

Planning Approximations to the Length of TSP and VRP Problems

This paper studies parsimonious, intuitive, and effective formulas to approximate the length of Traveling Salesman Problems (TSP) and Vehicle Routing Problems (VRP). Using intuition derived from continuous models and graph theory, a formula to approximate the length of vehicle routes is proposed. In instances with different patterns of customer spatial distribution, time windows, customer demands, and depot locations are used to test the proposed approximation. Regression results show that the approximation can reasonably predict the length of TSP and VRP problems in randomly generated problems and real urban networks. Expressions for the incremental cost of serving an additional customer or increasing the number of routes are derived and estimated. The main contribution of this paper is to develop and test intuitive approximations to TSP and VRP problem in general settings. The approximations are valuable for strategic and planning analysis of transportation and logistics problems

Climate Change Impact Assessment for Surface Transportation in the Pacific Northwest and Alaska

WA-RD 772.