258 research outputs found

    Assessing the Efficiency of Mass Transit Systems in the United States

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    Frustrated with increased parking problems, unstable gasoline prices, and stifling traffic congestion, a growing number of metropolitan city dwellers consider utilizing the mass transit system. Reflecting this sentiment, a ridership of the mass transit system across the United States has been on the rise for the past several years. A growing demand for the mass transit system, however, necessitates the expansion of service offerings, the improvement of basic infrastructure/routes, and the additional employment of mass transit workers, including drivers and maintenance crews. Such a need requires the optimal allocation of financial and human resources to the mass transit system in times of shrinking budgets and government downsizing. Thus, the public transit authority is faced with the dilemma of “doing more with less.” That is to say, the public transit authority needs to develop a “lean” strategy which can maximize transit services with the minimum expenses. To help the public transit authority develop such a lean strategy, this report identifies the best-in-class practices in the U.S. transit service sector and proposes transit policy guidelines that can best exploit lean principles built upon best-in-class practices

    The impact of hours-of-service regulations on transportation productivity and safety: A summary of findings from the literature

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    Since driver fatigue has known to be the primary cause of serious truck crashes, the Federal Motor Carrier Safety Administration (FMCSA) has attempted to implement new hours-of-service (HOS) regulations that aimed to promote safer driving environments. The new HOS regulations effective on October T‘ of2005, however, may lead to substantial cost increases for the trucking industry which will in turn hurt shippers and ultimately customers. For instance, motor carriers may need to hire additional drivers to comply with new HOS regulations requiring that drivers be placed out of service until they accumulated enough off-duty time. In particular, off-duty breaks required to refresh driving hours were increased to 10 consecutive hours from the old rule of eight cumulative hours. A chronic shortage of truck drivers coupled with new HOS regulations could further aggravate the driver recruitment and retention problems. In addition, due to potential loading/unloading delays and stiffer fines /penalties resulting from new HOS regulations, trucking productivity may decline. To help trucking firms cope with various challenges of new HOS regulations, this paper provides a systematic overview of prior literature that examines the impact of HOS on transportation productivity and safety in the U.S. It also discusses managerial implications of new HOS regulations

    The impact of lumper costs, empty miles, and shipment size on the profitability of motor carriers: A case study

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    The passage of landmark deregulatory reforms in the Motor Carrier of Act of 1980 has constantly pressured the U.S. trucking industry to reduce transportation costs. Thanks to such pressure, total logistics costs have declined from 16.5% in 1980 to 10.1% of gross domestic product (GDP) in 2000. In particular, transportation costs have fallen from 7.6% to 5.9% of GDP in 2000. Transportation cost savings definitely benefit shippers, while jeopardizing the viability of carriers. To help transportation carriers cope with enormous cost pressure, this paper examines the impact that “lumper” costs, empty miles, and shipment size have on the very competitive trucking industry. Through an actual case study of a firm based in the Southeast U.S., we illustrate how lumper costs, empty front-haul and backhaul, and shipping weight and pieces can adversely affect the trucking firm’s profitability

    Examining sources of driver turnover from a managerial perspective

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    There is growing concern about the declining profitability of the U. S. trucking industry. Such concerns often stem from the increased difficulty of recruiting and retaining qualified drivers. In fact, the trucking industry has been hit hard by shortages of qualified truck drivers over the last two decades. To cope with this chronic problem, trucking firms have attempted to formulate various driver recruitment and retention strategies that include pay raises, bonuses, equipment improvement, and adjustments in working hours. This article provides trucking firms with the means to implement a more effective driver recruitment and retention strategy by examining sources of the driver shortage problem

    Polarized Dendritic Cells for Tumor Immunotherapy

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    An elusive objective for tumor immunologists has been the development of an effective tumor vaccine capable of inducing potent immune responses to eliminate established tumors and induce long-term protective antitumor immunity. Dendritic cells (DCs) are potent inducers of immunity and represent a promising tool for the purpose of immune-based tumor therapies. However, DC-based vaccines have enjoyed only limited success in clinical trials, probably due to the use of immature/intermediate mature DCs that maintain tolerance during the steady state, or to the use of non-polarized DCs which lack the proper cytokine production that favors cellular immune responses needed to eliminate established tumors. The failure of past tumor vaccines demonstrates a need to examine and enhance immunization strategies on multiple levels. The underlying hypothesis for these studies was that combining a DC1 polarization signal with an effective antigen-loading strategy will result in enhanced tumor immunotherapy. Our first aim was to compare cytosolic and membrane-bound antigen presentation of tumor-derived proteins by DCs following three different antigen-loading strategies; coculture of DCs and tumor cells, feeding DCs with tumor lysate, and fusion of DCs and tumor cells. We demonstrated that both DC-tumor coculture and fusion result in a higher level of tumor-derived peptide presentation compared to feeding DCs with tumor lysate. Our second aim was to develop a murine DC1 polarization model to evaluate DC1-based tumor immunotherapy. Herein, we described the synergistic affect of TLR3 and TLR9 ligation on IL-12p70 production by murine DCs, characterizing the timing and exhaustion of IL-12p70 production. Furthermore, we examined the ability of polarized DCs to stimulate T cell proliferation and cytokine secretion in response to a model antigen in vitro. For our third aim we examined the capacity of DC1s to stimulate immune responses to a model antigen as well as native tumor antigens in vivo and tested the therapeutic effect of tumor-loaded DC1 vaccines. These studies demonstrate the ability of antigen-loaded polarized DCs to induce strong Th1-mediated anti-tumor immunity characterized by tumor infiltrating CD4+ T cells and macrophages, but not CD8+ T cells, resulting in tumor growth inhibition

    Evaluating the Comparative Efficiency of Eleven States’ Highway Expenditures

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    In an era of budget deficits and financial cutbacks, the efficiency of state highway finances dictates future investment in road construction and maintenance. Considering the significant impact of highway infrastructure on the survival and competitiveness of the logistics industry, this paper aims to develop a meaningful set of benchmarks that will guide the state government authority in making wise investment decisions regarding road construction and maintenance. In particular, we propose a data envelopment analysis that is proven to be useful for measuring the operational efficiency of various profit or non-profit organizations. Using the examples of state highway finances for Kentucky and other comparable states in the United States, this paper illustrates the usefulness of data envelopment analysis for the efficient allocation of financial resources to road construction and maintenance

    The impact of state taxes on the development and growth of the trucking industry

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    The presence of certain state taxes is believed to have a negative impact on truck registration and the location decisions of trucking firms. For example, in a metropolitan area that covers two or more states, a trucking firm might not choose to locate in the county that is in close proximity to the metropolitan area’s business districts, population centers, and largest concentration of customers, if that county is in a state that imposes the taxes. Instead, it might choose to locate in a county that belongs to another state that does not impose such taxes as long as that county is adjacent to the metropolitan area’s most industrialized districts. This paper examines the impact that state taxes have on the very competitive trucking industry. Through a case study of Kentucky, we illustrate how state taxes such as the motor vehicle usage tax and the weight distance tax can adversely affect the trucking firm’s decisions in registering and plating trucks, and in locating its facilities

    An examination of international logistics practices of U.S. logistics professionals

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    Over the last two decades, the growing interdependence of the world economy and the subsequent increase in foreign trade volume have contributed to the considerable expansion of global logistics activities. As global logistics operations became almost a daily routine for many logistics professionals, they have begun to search for adaptive logistics strategies to improve global competitiveness. To assist U.S. logistics professionals in fostering such strategies, this study empirically examines how the globalization of business has influenced the way U.S. logistics professionals adapt themselves to a dynamic international environment fraught with countless risks and complexities

    Benchmarking the operational efficiency of major U.S. trucking firms using data envelopment analysis

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    In an era of downsizing and financial cutbacks, the operational efficiency of trucking firms dictates their competitiveness and survival. In an effort to help trucking firms develop a winning formula in the fiercely competitive logistics industry, this research aims to develop a meaningful set of benchmarks that will set the tone for best practices. In particular, a data envelopment analysis (DEA) is described. DEA has proven to be useful for measuring the operational efficiency of various profit or non-profit organizations. Using the examples of major trucking businesses in the United States, the usefulness of data envelopment analysis for the continuous improvement of trucking services is illustrated

    Assuring quality at the source with varying worker skills: economic justification of the online repair policy

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    Traditionally, quality control on an assembly line has been conducted by quality inspectors at the end of the assembly line. Defective or incomplete parts identified during the production cycle are typically transferred to a separate repair shop where such parts are reworked, retested, re-inspected or replaced. In contrast, today’s repetitive manufacturing companies have begun to delegate the power and responsibility of quality inspection and control to assembly workers on the line. This so-called online (line-stop) repair policy has been receiving increased attention from many manufacturing companies. Through a series of computational experiments, this paper examines the effectiveness of the online repair policy, which empowers workers to assure quality on the assembly line. Under varied assembly line configurations, quality failure costs of the two repair policies are estimated and compared to verify the superiority of the online repair policy. The computational results indicate that the online repair policy can be far more effective in assuring quality and saving costs than the traditional offline repair policy
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