Showing papers on "Fleet management published in 1997"

Fleet sizing and empty equipment redistribution for center-terminal transportation networks

Abstract: Fleet sizing and empty equipment redistribution are important issues in managing transportation systems. Most of the mathematical models that have been developed for these problems are complex and computationally demanding, including dynamic linear programming and stochastic/dynamic mathematical programs. Our research takes an alternate approach by building from inventory theory and developing decentralized stock control policies for empty equipment. This approach is applied to hub-and-spoke networks (i.e., center-terminal networks), by first analytically modeling the stochastic processes representing various stock-control variables, and then comparing the analytical results to monte-carlo simulations. A decomposition approach is also developed to determine stock-out probabilities as a function of the fleet size as a whole, and as a function of localized control parameters.

Mileage and fuel consumption determination for geo-cell based vehicle information management

Abstract: A commercial vehicle fleet management system which integrates a vehicle on-board computer, a precise positioning system, and communication system to provide automated calculating and reporting of jurisdictional fuel taxes, road use taxes, vehicle registration fees, and the like. Also disclosed is an online mobile communication system and a system for monitoring carrier vehicle efficiency and vehicle and driver performance.

Fleet deployment optimization for liner shipping: an integer programming model

Abstract: Extending and improving an earlier work of the second author, an Integer Programming (IP) model is developed to minimize the operating and lay-up costs for a fleet of liner ships operating on various routes. The IP model determines the optimal deployment of an existing fleet, given route, service, charter, and compatibility constraints. Two examples are worked with extensive actual data provided by Flota Mercante Grancolombiana (FMG). The optimal deployment is solved for their existing ship and service requirements and results and conclusions are given.

Advances in the optimization of airline fleet assignment

Abstract: We present an advanced model for the formulation and solution of large scale fleet assignment problems that arise in the scheduling of air transportation. Fleet assignment determines the type of aircraft to operate each flight in a given schedule, subject to a variety of side constraints, due to marketing, operational, maintenance and crew restrictions. We model the problem as mixed-integer multicommodity flow on networks encoding activities linking flight departures. We focus on fully representing flight connection possibilities, while accurately capturing complex operational rules. We also provide a unified framework for the expression of resource constraints via piecewise linear penalties, which permits a profitability-based tradeoff between operational goals and revenue. Computational results on actual schedules show that high quality assignments for one-day problems can be obtained within an hour of computation. The use of the model at USAir results in an annual benefit of at least $15 million.

Static and dynamic time-space strategic models and algorithms for multilevel rail-car fleet management

Abstract: This paper deals with the design of dynamic time-space and calibrated static strategic planning models, along with solution algorithms, for the multilevel rail-car fleet management problem faced by RELOAD®, a branch of the Association of American Railroads (AAR). We discuss a prevalent fleet sizing management model that is static in nature, and propose an alternative dynamic model based on a time-space network representation. This model accurately represents the problem, and also provides information regarding the issue of storing and retrieving empty cars. A suitable decomposition heuristic, that is based on solving subproblems defined for overlapping time segments, is developed to solve this model. This heuristic is shown to recover an optimal solution for all the test problems with a reasonable effort. We also investigate a procedure for calibrating the static model based on this improved time-space representation. Our results show that for the static model, a calibrated use of available data can yield...

Commercial Fleet Demand for Alternative-Fuel Vehicles in California

Abstract: Fleet demand for alternative-fuel vehicles ('AFVs' operating on fuels such as electricity, compressed natural gas, or methanol) is investigated through an analysis of a 1994 survey of 2000 fleet sites in California. This survey gathered information on site characteristics, awareness of mandates and incentives for AFV operation, and AFV purchase intentions. The survey also contained stated preference tasks in which fleet decision makers simulated fleet-replacement purchases by indicating how they would allocate their choices across a 'selector list' of hypothetical future vehicles. A discrete choice model was estimated to obtain preference tradeoffs for fuel types and other vehicle attributes. The overall tradeoff between vehicle range and vehicle capital cost in the sample was $80/mile of range, but with some variation by fleet sector. The availability (density) of off-site alternative fuel stations was important to fleet operators, indicating that fleets are willing to trade off more fuel infrastructure for changes in other attributes, e.g. increased capital or operating costs, or more limited vehicle range. Public fleets (local and county government) were the most sensitive to the capital cost of new vehicles. Along with schools, they are the only fleet sector where reduced tailpipe emission levels are a significant predictor of vehicle choice. Fleet operators in the private sector base their vehicle selection less on environmental concerns than on practical operational needs.

TeleTruck : a holonic fleet management system

Abstract: In this paper we describe TeleTruck, a multiagent dispatching system that was developed in close cooperation with a forwarding company and that is capable of handling real-world requirements like dynamics and uncertainty. The main idea underlying the TeleTruck approach is the usage of holonic agents, i.e. agents composed of subagents that act in a corporated way. We describe the implementation in detail and point out the advantages of the holonic paradigm.

Container Logistics and its Management

Abstract: In this work research on container logistics and its management is presented. Contrary to the common approach of treating this as a mathematical problem and addressing it by operations research methods, this work regards the problem in a wider perspective. Instead of being limited to management of the physical system bringing about the movement of containers, container logistics management is regarded as also including demand management. The research aims at describing the logistics of the system in terms of how the various components in a container transport system interact and how the system interacts with its environment. Due to the limited previous research on container logistics and its management in a wider perspective, this work is primarily explorative and descriptive. Empirical studies of container flows are presented. Both the flow for an individual carrier and the total flow between a port and its hinterland have been studied and the studies reveal a low utilization of the containers. Containers were found to be stored empty for long periods of time at terminals, retained for a considerable time by customers and there was much transport of empty containers. The studies also revealed poor quality of the data in the computerized tracking systems with missing and erroneous data entries. In a study of ten of the world's twenty largest container shipping companies it was found that the use of advanced decision support systems, taking advantage of operations research or artificial intelligence technology, was scarce. Only one company reported to use such a system, which assigned priorities to depots, in day-to-day operations. The main logistical functions of the container are to create opportunities to exploit economies of scale and enabling vessels and vehicles to operate independently by decoupling them at terminals. Therefore, when deciding on actions to improve the utilization of containers the effect on other system components must be considered. Pooling is suggested as a way of increasing the utilization of the containers without constraining the operation of other, capital intensive, resources. Container logistics systems are characterized by high complexity and uncertainty. Much of the information relevant for decision-making is informal and the managers' experience is difficult to formalize. Therefore successful systems for container logistics management must take advantage of both human and computerized information processing. It is suggested to engage theories from cybernetics and information theory as a theoretical framework for logistics systems analysis. Even if this is only done to a limited extent in this research, due to being considered at a late stage of the research, these theories show a strong explanatory ability.

The AFV credit program and its role in future AFV market development

Abstract: The Energy Policy Act of 1992 (EPACT) requires that fleet operators throughout the country begin purchasing alternative fuel vehicles (AFVs). In EPACT, Congress also established an AFV credit program, which uses market forces to provide flexibility to regulated entities. Under the credit program, regulated fleet operators can obtain credits for purchasing more AFVs than required; fleet operators can then sell these credits to other fleet operators who choose to purchase fewer AFVs than required. Because of network effects inherent in AFV markets, the credit program may allow AFVs to ‘cluster’ about urban hubs. This paper explores future AFV market development in light of the AFV credit program and the network effects of the AFV market.

Communications and Tracking for Construction Vehicles

Abstract: Advanced communication and tracking systems (ACTS) have potential to improve the efficiency of vehicle fleets such as dump trucks, concrete trucks, low boy trailers, and scrapers. Commercial applications of ACTS in long distance trucking and inventory/materials tracking have been successful. ACTS can be seen as having significant prospects in construction fleet management, especially for complex operations where dispatchers must know vehicle locations and communicate constantly with drivers. This paper describes three advanced systems: signaling systems, continuous communication and tracking systems, and radio frequency identification. Three conceptual examples follow that show how these systems can be implemented and demonstrate their potential value in construction fleet management.

Sources of fuzziness in vehicle maintenance management

Abstract: Deals with sources of fuzziness in individual parts and stages of maintenance and utilization of vehicles in large fleets. Effective vehicle fleet maintenance management requires data on reliability and maintainability. In most cases, however, available data are insuffucient for proper statistical identification of performance, making it impossible to define an adequate model to support decision‐making procedures. Demonstrates that, in such cases, the fuzzy set theory is convenient for modelling these processes so as to enable decision making and maintenance management.

Real-time information for improved efficiency of commercial vehicle operations

Abstract: Intelligent Transportation Systems (ITS) harness advanced communications and computation technologies in order to make transportation systems more efficient. This work is concerned with the application of ITS to commercial vehicle operations and freight mobility; it identifies and investigates potential uses of real-time information for the efficient management of carrier operations. In truckload and less-than-truckload operations, carriers typically know only a portion of the loads that must be moved more than a few hours before the moves must take place. Therefore, the assignment of an available driver to a load takes place in real-time or shortly after the request is received. The load acceptance decision made by a carrier must also be executed in real-time, and may have a significant impact on the carrier's ability to accept other loads requested in the near future. In this context vehicle to load assignments as well as the sequence in which loads are to be served may be revisited as demands unfold and traffic network conditions change. Because of the speed with which decisions must be made, the number of possible choices and the fact that the system is changing dynamically and often, unpredictably, locally oriented decision rules offer a promising alternative to approaches seeking global optimality or those which take into account long term or forecast information. The main hypotheses examined are, that real-time information on vehicle locations and demands can increase the efficiency of carrier fleet operations with respect to measures of trucking company profitability and responsiveness to customer requests, and, that real-time operational strategies perform well, compared to those requiring less real-time information, under certain conditions with respect to fleet size, level of demand and service deadlines. Operational strategies which take advantage of real-time information and, which include methods to perform load acceptance, assignment and re-assignment are examined both analytically, and in simulation framework developed to test these and related strategies under a variety of operating assumptions. Quantitative estimates of the benefits of real-time information for vehicle assignment and routing decisions for trucking operations are developed.

Orange County Transit Probe Evaluation: Phase I Institutional Findings

Abstract: This report documents the institutional issues that have faced the Orange County probe project, a multi-agency project designed to equip a fleet of buses with Global Positioning System (GPS) based tracking equipment and to use tracking data for multiple purposes. The usefulness of the data involve: 1) bus schedule adherence and fleet management; 2) collection of information on roadway traffic congestion; and, 3) dissemination of transit data to patrons.

Orange County Transit Probe Evaluation: Phase I Institutional Findings

Abstract: This report documents the institutional issues that have faced the Orange County probe project, a multi-agency project designed to equip a fleet of buses with Global Positioning System (GPS) based tracking equipment and to use tracking data for multiple purposes. The usefulness of the data involve: 1) bus schedule adherence and fleet management; 2) collection of information on roadway traffic congestion; and, 3) dissemination of transit data to patrons.

Systems planning for automated commercial vehicle licensing and permitting systems: national its/cvo program requirements

Abstract: This report describes the work of the study, "Systems Planning for Automated Commercial Vehicle Licensing and Permitting Systems". The objective of this study is to define the market, organization, and resource requirements for a national program for the application of Intelligent Transportation Systems (ITS) to commercial vehicle operations (CVO). The report assesses the public and private sector markets for ITS/CVO products and services. The public sector analysis includes a review of the major CVO regulatory processes, the level and distribution of transactions, and the major regulatory issues relevant to the development of a national ITS/CVO program. The private sector analysis includes an examination of how major operating characteristics such as fleet size and geographic range shape the trucking industry's need for new technologies; the identification of major freight generation centers and freight corridors in the United States; and a description of the major regional markets in which the motor carrier industry operates. In addition, the report reviews more than 50 government and public/private initiatives to develop, test, and deploy elements of the ITS/CVO program in four areas: credentials administration, enforcement, fleet and vehicle management, and highway traffic management. Finally, the report reviews the ITS/CVO program's current market, organization, and resource strategies, and recommends new directions and strategies to strengthen the program.

Cost‐effectiveness and officer morale of a personally assigned patrol vehicle program: A comparative analysis

Abstract: Presents a study which compares two police fleet management programs in San Diego County and combines both qualitative and quantitative data collection methods to evaluate the costs and effectiveness of a personally‐assigned vehicle program to that of a conventional pool car program. Concludes that personally‐assigned vehicles are most cost‐effective to maintain. Moreover, officers report a higher level of satisfaction using a personally‐assigned vehicle than a shared patrol car. Finds that those officers with individually‐assigned vehicles have less job stress and higher levels of morale.

Benefits of gps based automatic vehicle location for fleet management and improved transit operations

Abstract: In 1991 the Regional transportation district of Denver, CO contracted to deploy a GPS based Computer Aided Dispatch/Automatic Vehicle Locator (CAD/AVL) system. The design, development, and deployment of the eventual SmartTrack Vehicle Management System was the effort of Westinghouse's transportation Management System division located in Linthicum, MD, now known as Raytheon E-Systems, TMS. In addition to a newer and more reliable radio system, Denver RTD desired to improve the capability of dispatchers to control on-street operations and emergencies. It was also hoped the new system would provide data collecting capabilities that could be utilized for real time information to the public. The addition of a GPS solution for location applications was, at that time, just becoming available for civilian use. Although initially fielded in 1993, acceptance testing was completed in March of 1996. TMS provided much of the final manpower and support to reach acceptance and is currently performing post acceptance warranty services for RTD. Similar systems have also been fielded for Milwaukee County Transit System (MCTS) in 1993 and for MARTA in Atlanta in 1996, COLTS in Scranton, PA, Metro in Des Moines, IA, and suburban Detroit (in 1996) by TMS. SmartTrack and/or advanced traveller information systems are also underway for Baltimore (MTA), Broward County transit (BCt) in Pompano Beach, FL, and NYCMTA. The objective of this paper is to present the benefits of an automatic vehicle location system for fleet management and will deal primarily with information based on the Denver RTD solution. Information will be collected, evaluated and qualified for the other systems as well, as daily operations allow, to be presented at future forums.

Orbtrac-100 automatic vehicle location and fleet management system for state and municipal fleets

Abstract: ORBTRAC-100 is a fully-integrated real-time information system for State and Municipal fleet applications. Primary features include automatic vehicle location (AVL), two-way messaging, sensor data collection and off-line data analysis tools linked to a geographic information database (GIS). ORBTRAC-100 is a comprehensive suite of mobile communications, electronics and software that will enhance the performance of fleet operations. The benefits and design features are described. For the covering abstract, see IRRD 490001.

The liselec system: design and first experience

Abstract: The Liselec system offers a new form of personal transport thanks electrical private cars, available on a self-service basis to subscribers at stations installed across the area concerned. This project has recently passed an important stage with the creation pilot fleet of 10 vehicles fitted with the equipment required for operation on a self-service basis: the Liselec demonstrator. This document is an initial report on the demonstrator and describes t next phases of the Liselec project, after reviewing the main characteristics of the system. For the covering abstract, see IR 490001.

Methods for predicting bus travel times using a signpost positioning system

Abstract: Accurate prediction of travel times of buses has many applications in the field of Intelligent Transport Systems (ITS). It can be used for providing public transport passengers with reliable information concerning the arrival times of the vehicles in the service. It can also be used for fleet management purposes to improve the quality of the service and for traffic management purposes to provide priority for buses at traffic lights. This paper describes the derivation and results of implementing several schemes for forecasting future arrival times of the Sydney Airport Express buses, based on positioning data collected from the ANTSS (Automatic Network Travel Time System). This work is part of a project for evaluating and improving the operation of this service. For the covering abstract, see IRRD 490001.

The experience of establishing a prototype of traveller information system in taiwan

Abstract: This research provides applications of advanced information in road transport operations with the help of computer and communication technologies referred to as intelligent transportation systems (ITS). In this research, the authors develop a prototype of Advanced Travel Information Systems (ATIS) providing information to drivers on the Sun Yat-sen National Freeway about their location and alternative routes in the highway system. A prototype is also developed of Advanced Public Transportation Systems (APTS) providing public bus users with dynamic information about bus location and providing public bus manager monitoring systems to improve fleet management. With the bus location and speed information, the system provides the speed information of the national freeway alternative routes to the drivers. Both APTS and ATIS are based on Automatic Vehicle Location (AVL) with Global Positioning System (GPS). For the covering abstract, see IRRD 490001.

An Optimal Control Formulation of Large-Scale Multiclass Machine Scheduling Problems

Abstract: We consider a broad class of machine scheduling problems that arise in a spatial setting. Machines, which might be drivers and crews, or equipment such as trucks, locomotives or aircraft, need to be assigned to a sequence of jobs over time and space. In practice, the data is often changing in real-time, and schedulers need a rapid, on-line scheduling system to assign machines to jobs. Since there is often local data available to the scheduler that may not be known to the machine, it is often more important to present a set of ranked options to the scheduler than it is to develop the “optimal” solution. In this paper, we use a linearization approximation to develop a control strategy that provides on-line control information, drawing on a concept from work in fleet management called a istics queueing network

Fleet fuel card market swells as companies seek to cut costs

Abstract: SUBTITLE: RECOGNIZING THAT 63 BILLION GALLONS OF FUEL IS CONSUMED BY FLEETS EACH YEAR, CORPORATE AND FUEL COMPANY PARTNERSHIPS HAVE BEEN GAINING IN POPULARITY: ANOTHER REASON IS TOUGHER EPA REGULATIONS AND LIABILITY ISSUES CONCERNING UNDERGROUND FUEL TANKS. WITH DIRECTORY OF CARD PROGRAMS.

Where have all the jobs gone for fleet managers

Abstract: SUBTITLE: PROMOTED, RETIRED, QUIT, OR FIRED -- FLEET MANAGERS WHO LEAVE THEIR POSTS ARE NOT BEING REPLACED 24 PERCENT OF THE TIME, ACCORDING TO A RECENT SURVEY: OF THE NEW APPOINTEES, 77.6 PERCENT HAD NO PRIOR FLEET EXPERIENCE.

Gps-gis application in real-time traffic control, congestion management and fleet management

Abstract: This paper examines the use of GPS in real-time vehicle tracking, congestion monitoring and vehicle performance monitoring, for both private vehicles and public transport. It addresses these issues from a practical point of view and provides some results on accuracy and reliability issues for GPS in urban traffic situations. The paper indicates how GPS data can be used to derive a number of parametric measures of congestion and in automatic vehicle identification and location. The paper demonstrates the value of integration of GPS with Geographical Information Systems (GIS) software, especially for fleet management and traffic systems control. (A) For the covering abstract see IRRD 887751.