39,647 research outputs found

    The Right Track: Building a 21st Century High-Speed Rail System for America

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    Provides an overview of U.S. investment in high-speed intercity passenger rail, its economic and environmental benefits, analyses by region, and key steps for building an efficient network, including balancing private investment with public safeguards

    An optimization model for line planning and timetabling in automated urban metro subway networks

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    In this paper we present a Mixed Integer Nonlinear Programming model that we developed as part of a pilot study requested by the R&D company Metrolab in order to design tools for finding solutions for line planning and timetable situations in automated urban metro subway networks. Our model incorporates important factors in public transportation systems from both, a cost-oriented and a passenger-oriented perspective, as time-dependent demands, interchange stations, short-turns and technical features of the trains in use. The incoming flows of passengers are modeled by means of piecewise linear demand functions which are parameterized in terms of arrival rates and bulk arrivals. Decisions about frequencies, train capacities, short-turning and timetables for a given planning horizon are jointly integrated to be optimized in our model. Finally, a novel Math-Heuristic approach is proposed to solve the problem. The results of extensive computational experiments are reported to show its applicability and effectiveness to handle real-world subway networksComment: 30 pages, 6 figures, 9 table

    Stochastic Improvement of Cyclic Railway Timetables

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    Real-time railway operations are subject to stochastic disturbances. However, a railway timetable is a deterministic plan. Thus a timetable should be designed in such a way that it can cope with the stochastic disturbances as well as possible. For that purpose, a timetable usually contains time supplements in several process times and buffer times between pairs of consecutive trains. This paper describes a Stochastic Optimization Model that can be used to allocate the time supplements and the buffer times in a given timetable in such a way that the timetable becomes maximally robust against stochastic disturbances. The Stochastic Optimization Model was tested on several instances of NS Reizigers, the main operator of passenger trains in the Netherlands. Moreover, a timetable that was computed by the model was operated in practice in a timetable experiment on the so-called Ć¢ā‚¬Å“ZaanlijnĆ¢ā‚¬. The results show that the average delays of trains can often be reduced significantly by applying relatively small modifications to a given timetable.Railway Timetabling;Stochastic Optimization;Robustness

    Integer programming based solution approaches for the train dispatching problem

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    Railroads face the challenge of competing with the trucking industry in a fastpaced environment. In this respect, they are working toward running freight trains on schedule and reducing travel times. The planned train schedules consist of departure and arrival times at main stations on the rail network. A detailed timetable, on the other hand, consists of the departure and arrival times of each train in each track section of its route. The train dispatching problem aims to determine detailed timetables over a rail network in order to minimize deviations from the planned schedule. We provide a new integer programming formulation for this problem based on a spacetime networkĶ¾ we propose heuristic algorithms to solve it and present computational results of these algorithms. Our approach includes some realistic constraints that have not been previously considered as well as all the assumptions and practical issues considered by the earlier works

    Operations research in passenger railway transportation

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    In this paper, we give an overview of state-of-the-art OperationsResearch models and techniques used in passenger railwaytransportation. For each planning phase (strategic, tactical andoperational), we describe the planning problems arising there anddiscuss some models and algorithms to solve them. We do not onlyconsider classical, well-known topics such as timetabling, rollingstock scheduling and crew scheduling, but we also discuss somerecently developed topics as shunting and reliability oftimetables.Finally, we focus on several practical aspects for each of theseproblems at the largest Dutch railway operator, NS Reizigers.passenger railway transportation;operation research;planning problems

    High-Speed Rail Projects in the United States: Identifying the Elements of Success-Part 2, MTI 06-03

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    In August 2005, the Mineta Transportation Institute issued the report, High-Speed Rail Projects in the United States: Identifying the Elements for Success. The report noted that since the 1960s, highspeed ground transportation (HSGT) has ā€œheld the promise of fast, convenient, and environmentally sound travel for distances between 40 and 600 miles.ā€ After briefly discussing the different experiences with HSGT between the United States and its Asian and European counterparts, the report proceeded to review three U.S. casesā€”Florida, California, and the Pacific Northwestā€”as a means for identifying lessons learned for successfully implementing high-speed rail (HSR) in the United States. This report is, in essence, volume 2 of the previous study. Also using a comparative case study approach, this effort adds to the earlier work with three additional casesā€”the Chicago Hub, the Keystone Corridor, and the Northeast Corridor (NEC). As with the earlier report, the goal of this study is to identify lessons learned for successfully implementing HSR in the United States. Given the early stages of most of these projects, ā€œsuccessā€ is defined by whether a given HSR project is still actively pursuing development or funding. However, in the case of the Northeast Corridor, a fuller discussion of success is provided since HSR has been implemented on that corridor for some time now

    High-Speed Rail: The Wrong Road for America

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    In the face of high energy prices and concerns about global warming, environmentalists and planners offer high-speed rail as an environmentally friendly alternative to driving and air travel. California, Florida, the Midwest, and other parts of the country are actively considering specific high-speed rail plans. Close scrutiny of these plans reveals that they do not live up to the hype. As attractive as 110-to 220-mile-per-hour trains might sound, even the most optimistic forecasts predict they will take few cars off the road. At best, they will replace for profit private commuter airlines with heavily subsidized public rail systems that are likely to require continued subsidies far into the future. Nor are high-speed rail lines particularly environmentally friendly. Planners have predicted that a proposed line in Florida would use more energy and emit more of some pollutants than all of the cars it would take off the road. California planners forecast that high-speed rail would reduce pollutionand greenhouse gas emissions by amere 0.7 to 1.5 percent -- but only if ridership reached the high end of projected levels. Lower ridership would nullify energy savings and pollution reductions. These assessments are confirmed by the actual experience of high-speed rail lines in Japan and Europe. Since Japan introduced high-speed bullet trains, passenger rail has lost more than half its market share to the automobile. Since Italy, France, and other European countries opened their high-speed rail lines, rail's market share in Europe has dwindled from 8.2 to 5.8 percent of travel. If high-speed rail doesn't work in Japan and Europe, how can it work in the United States? As megaprojects -- the California high-speed rail is projected to cost 33to33 to 37 billion -- high-speed rail plans pose serious risks for taxpayers. Costs of recent rail projects in Denver and Seattle are running 60 to 100 percent above projections. Once construction begins, politicians will feel obligated to throw good taxpayers' money after bad. Once projects are completed , most plans call for them to be turned over to private companies that will keep any operational profits,while taxpayers will remain vulnerable if the trains lose money. In short, high-speed rail proposals are high cost, high-risk megaprojects that promise little or no congestion relief, energy savings, or other environmental benefits. Taxpayers and politicians should be wary of any transportation projects that cannot be paid for out of user fees
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