首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Ferreira  Luis 《Transportation》1997,24(2):183-200
As privatisation of railway systems reach the political agendas in a number of countries, the separation of track infrastructure from train operations is seen as providing the vehicle which will improve profitability within the rail industry. This paper deals with three main issues related to such separation within a freight railway focus, namely: investment appraisal; track standards and maintenance; and train operating performance. The conflicts of interest between the owners of track and their client operators are discussed in detail. Costs related to track capacity and congestion need to be taken into account, given that additional trains are likely to lead to increased risk of delays to existing services. The paper discusses the use of a travel time reliability model to estimate the additional costs imposed on the system through the introduction of specific train services.It is concluded that investment in individual elements of railway infrastructure must be integrated with the overall financial and customer service strategies of both operators and owners. As an alternative to current practices, a hybrid model of track ownership is put forward here. Under such a model, a joint-venture company with equity from the main ÒplayersÓ would be owner of track. This would allow some of the benefits of vertical integration to be retained, whilst providing fair access to new operators.  相似文献   

2.
In this paper techniques for scheduling additional train services (SATS) are considered as is train scheduling involving general time window constraints, fixed operations, maintenance activities and periods of section unavailability. The SATS problem is important because additional services must often be given access to the railway and subsequently integrated into current timetables. The SATS problem therefore considers the competition for railway infrastructure between new services and existing services belonging to the same or different operators. The SATS problem is characterised as a hybrid job shop scheduling problem with time window constraints. To solve this problem constructive algorithm and meta-heuristic scheduling techniques that operate upon a disjunctive graph model of train operations are utilised. From numerical investigations the proposed framework and associated techniques are tested and shown to be effective.  相似文献   

3.
T. L. Beagley 《运输评论》2013,33(4):389-395
A conference organized in December 1993 by ESTI and CER discussed the major challenges facing the European railway industry. There are great opportunities in prospect for such an environmentally friendly industry, but there are many structural, financial and operational problems to overcome. The 1991 European Union Policy laid down the separation of the management of operation and infrastructure from the provision of railway transport services: measures for improving the financial structure of undertakings; and the introduction of international competition. The conference discussed the progress in restructuring, technical harmonization and interoperability and the practical issues involved in introducing competition.  相似文献   

4.

In intermodal logistics, combined transport operators and railway companies are engaged in the development of efficient block train concepts. The proportion of transport using single railway wagons is decreasing because of its poor time-quality ratio. In future, transport services will be focussed on industrial zones and large cities that offer the transport volumes required for direct train operation. In this regard, it will become more difficult for regions with smaller load volumes to be integrated into a combined transport network. In order to confront this trend, new concepts for bundling transport volumes have to be developed. One such concept is the 'mega hub'. The core idea is to interchange load units between several block trains during a short stop at an intermodal terminal. The paper provides an overview of the operating concept of the mega hub and the opportunities for intermodal transport operators.  相似文献   

5.
To achieve transport cost reductions and to reduce the environmental impact of road transport, different European countries are allowing or testing longer and heavier vehicles on their road network. In Belgium, the Flanders region started a trial in 2015 allowing a limited number of longer and heavier vehicles on a selection of approved routes. A concern among intermodal operators is however that an allowance of longer and heavier vehicles could trigger a reverse modal shift away from rail and inland waterways container transport. Starting from experiences in other European countries, this paper discusses the potential spatial impact of allowing longer and heavier vehicles on the market areas of intermodal transhipment terminals using a geographic information systems-based location analysis model. In a second step, external transport costs are incorporated in this model, to quantify the spatially diversified societal costs of a potential reverse modal shift.  相似文献   

6.
With a large number of railway development projects in Europe and worldwide, which once completed will be serving rail passengers of the future, this paper aims to take a step back and evaluate current railway systems performance. The objectives are to compare statistical data on various passenger-related parameters of the railway system in a number of selected European countries and draw conclusions on the level of their performance when compared to the European average.Analyses of publically available statistical data, extracted from the Eurostat service at a European level will allow for a comparison of various indicators which influence the performance of the railway systems from an infrastructure and operational perspectives. The analyses will also allow identifying key performance indicators for the accurate assessment of the rail systems.The paper will highlight case studies for various parameters which are important to stakeholders of the railways, including infrastructure managers, rail operators, policy makers and the end users. This knowledge will be to the benefit of today’s railway industry as well as the rail systems of the future, as it will show trends drew upon existing data which might continue in the future.  相似文献   

7.
In 2008, the European Commission, the European Parliament and the European Council agreed on including international aviation in the already existing European Union carbon market. From 2012, allowances will be required for all international flights landing at and departing from any airport in the EU. Domestic aviation will be subject to the same rules as international air traffic. Model-based empirical estimations presented in this paper indicate a diverse set of effects influencing competition between European and non-European aircraft operators. Initially, this paper provides an overview on recent political developments on EU as well as on International Civil Aviation Organisation level on the subject of emissions trading and aviation. Subsequently, our modelling approach and the main results concerning impacts on operating costs, ticket prices and cargo rates for European and non-European aircraft operators are presented and discussed. Finally, conclusions about the impacts on competition between European and non-European airlines are drawn.  相似文献   

8.
Abstract

Open access reforms to railway regulations allow multiple train operators to provide rail services on a common infrastructure. As railway operations are now independently managed by different stakeholders, conflicts in operations may arise, and there have been attempts to derive an effective access charge regime so that these conflicts may be resolved. One approach is by direct negotiation between the infrastructure manager and the train service providers. Despite the substantial literature on the topic, few consider the benefits of employing computer simulation as an evaluation tool for railway operational activities such as access pricing. This article proposes a multi-agent system (MAS) framework for the railway open market and demonstrates its feasibility by modelling the negotiation between an infrastructure provider and a train service operator. Empirical results show that the model is capable of resolving operational conflicts according to market demand.  相似文献   

9.
In the United States the railroads are the only intercity freight carriers that own the vehicles, routes and terminals that they use. Routes and terminals are natural monopolies and need regulation; the operation of vehicles is naturally competitive and, at most, needs antitrust. On this view, the operation of rail vehicles should be divested and deregulated; the routes and terminals need improved regulation. The present objective is to propose a method of regulating the tolls that would be charged by the route operators. The network would be partitioned into separately owned route segments. Each segment would be operated by a supplier of route services under a franchise bidding scheme. The unit of service would be a linear space on a track; this unit would equal the length of the train plus a safety interval, and it would move along the track at a standard speed. The heart of the proposal consists of a rule for pricing this space. A unit of route service is produced if and only if the revealed gain from exchange is nonnegative, and any unit produced is sold to that train operator who values it most. Price equals incremental cost, and a bidding scheme ensures that the subsidies will be such as either to yield normal profits in the long run or else to cause the route segment to be shut down.  相似文献   

10.
11.
Transport demand for containers has been increasing for decades, which places pressure on road transport. As a result, rail transport is stimulated to provide better intermodal freight transport services. This paper investigates mathematical models for the planning of container movements in a port area, integrating the inter-terminal transport of containers (ITT, within the port area) with the rail freight formation and transport process (towards the hinterland). An integer linear programming model is used to formulate the container transport across operations at container terminals, the network interconnecting them, railway yards and the railway networks towards the hinterland. A tabu search algorithm is proposed to solve the problem. The practical applicability of the algorithm is tested in a realistic infrastructure case and different demand scenarios. Our results show the degree by which internal (ITT) and external (hinterland) transport processes interact, and the potential for improvement of overall operations when the integrated optimization proposed is used. Instead, if the planning of containers in the ITT system is optimized as a stand-alone problem, the railway terminals may suffer from longer delay times or additional train cancellations. When planning the transport of 4060 TEU containers within one day, the benefits of the ITT planning without considering railway operations account for 17% ITT cost reduction but 93% railway operational cost growth, while the benefits of integrating ITT and railway account for a reduction of 20% in ITT cost and 44% in railway operational costs.  相似文献   

12.
Jeremy Drew 《运输评论》2013,33(2):223-237
Abstract

This paper reviews and analyses the benefits for rail freight customers of the two principal models for introducing competition in main line railway networks: (1) the vertical separation of infrastructure from operations; and (2) the introduction of competition providing other operators with open access to the network. The paper shows that traffic growth has generally been higher in those European countries that have liberalized most. It then examines in detail the impact of restructuring in Great Britain in terms of the competition, freight rates and traffic growth. The paper concludes that vertical separation benefits freight customers more than just open access.  相似文献   

13.
Abstract

The institutional environment of rail transport has changed as a result of recent European directives, but the changes have taken different forms from one country to another. In the case of international maritime chains, the development of door‐to‐door services makes inland haulage from the loading and discharging ports extremely important, and it highlights the need to reshape the rail freight industry. This paper analyses the degree of involvement of different actors drawn from the maritime industry in developing and commercializing rail services in the changing regulatory environment. Several maritime operators, shipping lines, port‐handling companies and port authorities have been involved in some container rail services since the early days of liberalization. Their commitments take very different forms, however. Whereas contracts are mainly used for the provision of service, particularly for train haulage, integration by means of shareholding or creating subsidiaries or joint ventures is used for marketing. Important differences between France, the UK, Germany and the Netherlands are detailed. In the latter two countries, there is more involvement in the provision of rail services. Marketing rail services appear to be the main strategic issue for the maritime operators in all four countries  相似文献   

14.
We develop a model of the costs of railroad operations which allows examination of the effects of network and input price changes, and which allows us to estimate marginal operating costs on an origin-destination basis. A primary potential use of this model is pricing of specific services. Economic theory is used to specify a marginal cost function which is estimated using data from the network analysis. This provides a convenient summary of the information in the network model, and could be used to investigate the impacts of changes in prices of input, such as fuel, on marginal operating costs.  相似文献   

15.
This study addresses the problem of scheduling a fleet of taxis that are appointed to solely service customers with advance reservations. In contrast to previous studies that have dealt with the planning and operations of a taxi fleet with only electric vehicles (EVs), we consider that most taxi companies may have to operate with fleets comprised of both gasoline vehicles (GVs) and plug-in EVs during the transition from GV to (complete) EV taxi fleets. This paper presents an innovative multi-layer taxi-flow time-space network which effectively describes the movements of the taxis in the dimensions of space and time. An optimization model is then developed based on the time-space network to determine an optimal schedule for the taxi fleet. The objective is to minimize the total operating cost of the fleet, with a set of operating constraints for the EVs and GVs included in the model. Given that the model is formulated as an integer multi-commodity network flow problem, which is characterized as NP-hard, we propose two simple but effective decomposition-based heuristics to efficiently solve the problem with practical sizes. Test instances generated based on the data provided by a Taiwan taxi company are solved to evaluate the solution algorithms. The results show that the gaps between the objective values of the heuristic solutions and those of the optimal solutions are less than 3%, and the heuristics require much less time to obtain the good quality solutions. As a result, it is shown that the model, coupled with the algorithms, can be an effective planning tool to assist the company in routing and scheduling its fleet to service reservation customers.  相似文献   

16.
Planning and operating railway transportation systems is an extremely hard task due to the combinatorial complexity of the underlying discrete optimization problems, the technical intricacies, and the immense size of the problem instances. Because of that, however, mathematical models and optimization techniques can result in large gains for both railway customers and operators, e.g., in terms of cost reductions or service quality improvements. In the last years a large and growing group of researchers in the OR community have devoted their attention to this domain developing mathematical models and optimization approaches to tackle many of the relevant problems in the railway planning process. However, there is still a gap to bridge between theory and practice (e.g. Cacchiani et al., 2014; Borndörfer et al., 2010), with a few notable exceptions. In this paper we address three individual success stories, namely, long-term freight train routing (part I), mid-term rolling stock rotation planning (part II), and real-time train dispatching (part III). In each case, we describe real-life, successful implementations. We will discuss the individual problem setting, survey the optimization literature, and focus on particular aspects addressed by the mathematical models. We demonstrate on concrete applications how mathematical optimization can support railway planning and operations. This gives proof that mathematical optimization can support the planning of railway resources. Thus, mathematical models and optimization can lead to a greater efficiency of railway operations and will serve as a powerful and innovative tool to meet recent challenges of the railway industry.  相似文献   

17.
The urban bus industry in Korea used to be controlled to provide stable transport services and enable operators to secure proper profits, but there were adverse effects within the industry such as inadequate business management and a downward spiral of low quality services resulting from lower fares. The government began easing restrictions on entry, operation, fares, and some conditions and procedures for licensing in the late 1980s, until in 1993, the government published a package of deregulatory measures that were considerably more drastic than those previously seen, such as freely adjusting the number of vehicles within 10%, easing the restrictions and requirements for operators’ employing staff and drivers, and improving the fare system. However, these measures seem to have been introduced too late and too luke‐warmly to encourage new entrants to the industry. Therefore, to gain the desirable effects of deregulation and to secure the development of the urban bus sector, there needs to be provision of a market atmosphere and greater scope for free competition; a positive attitude among operators for efficient business management and new services; and alert observation and monitoring by passengers.  相似文献   

18.
European legislation implies the use of marginal social cost pricing in rail access charges levied on rail operators. Thus, they may include specific environmental charges to internalise the impacts of rail transport. However, when applying these principles in practice, several difficulties call for second-best settings adapted to the particularities of the rail market. In this context, few European railway administrations are already implementing rail access charges with an environmental dimension. This paper reviews the literature on the issue and assesses the current European experience in noise and air pollution rail charges. For this purpose, an analytical framework is built on the definition of four basic dimensions: charging approach, allocation of abatement efforts, degree of differentiation and intermodal approach. The qualitative examination of the existing systems suggests that the level of environmental surcharges can be generally increased given the low substitutability between rail and road and that the range of abatement possibilities should be enlarged by further differentiating charges. It is also found that the pricing scope should be adapted to achieve particular cost-efficient allocations of abatement efforts among rail operators and upstream agents. Finally, further research requirements for a quantitative assessment are defined.  相似文献   

19.
Electric vehicles (EVs) are promising alternative to conventional vehicles, due to their low fuel cost and low emissions. As a subset of EVs, plug-in hybrid electric vehicles (PHEVs) backup batteries with combustion engines, and thus have a longer traveling range than battery electric vehicles (BEVs). However, the energy cost of a PHEV is higher than a BEV because the gasoline price is higher than the electricity price. Hence, choosing a route with more charging opportunities may result in less fuel cost than the shortest route. Different with the traditional shortest-path and shortest-time routing methods, we propose a new routing choice with the lowest fuel cost for PHEV drivers. Existing algorithms for gasoline vehicles cannot be applied because they never considered the regenerative braking which may result in negative energy consumption on some road segments. Existing algorithms for BEVs are not competent too because PHEVs have two power sources. Thus, even if along the same route, different options of power source will lead to different energy consumption. This paper proposes a cost-optimal algorithm (COA) to deal with the challenges. The proposed algorithm is evaluated using real-world maps and data. The results show that there is a trade-off between traveling cost and time consumed when driving PHEVs. It is also observed that the average detour rate caused by COA is less than 14%. Significantly, the algorithm averagely saves more than 48% energy cost compared to the shortest-time routing.  相似文献   

20.
Train dispatching is vital for the punctuality of train services, which is critical for a train operating company (TOC) to maintain its competitiveness. Due to the introduction of competition in the railway transport market, the issue of discrimination is attracting more and more attention. This paper focuses on delivering non-discriminatory train dispatching solutions while multiple TOCs are competing in a rail transport market, and investigating impacting factors of the inequity of train dispatching solutions. A mixed integer linear programming (MILP) model is first proposed, in which the inequity of competitors (i.e., trains and TOCs) is formalized by a set of constraints. In order to provide a more flexible framework, a model is further reformulated where the inequity of competitors is formalized as the maximum individual deviation of competitors’ delay cost from average delay cost in the objective function. Complex infrastructure capacity constraints are considered and modelled through a big M-based approach. The proposed models are solved by a standard MILP solver. A set of comprehensive experiments is conducted on a real-world dataset adapted from the Dutch railway network to test the efficiency, effectiveness, and applicability of the proposed models, as well as determine the trade-off between train delays and delay equity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号