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1.
In the course of Deutsche Bahn's new high - speed railway line between Nuremberg and Ingolstadt, a number of tunnels are being constructed, with a total length of about 15 km. One of the longest tunnel is the 7,250 m long Irlahüll tunnel.The tunnel was driven in karst geology. It was not expected that karst phenomena would be so widespread. This forced client, designer and contractor to take a new approach to the project. Different tools were developed to handle the problems on site. Additional site investigations had to be performed to identify karst phenomena in the vicinity of the tunnel. For validating the stability and serviceability of the tunnel, a new way of defining the probability of failure of the construction had to be found. Based on the experience of the tunnel driving at the high - speed railway line in Germany between Nuremberg and Ingolstadt, two different methods of tunnelling are discussed: Drill and blast ( New Austrian Tunnelling Method: NATM) and the use of tunnel boring machines (TBM).  相似文献   

2.
Kane  Lisa  Del Mistro  Romano 《Transportation》2003,30(2):113-131
The 1990s saw the emergence of influential transport legislation both in the UK and in the USA. This "watershed" period appears to indicate that a significant turning point in transport policy is underway. There is now a need to re-evaluate how transport planning is done, and to consider changes to commonly used methods. Criticisms of urban transport planning are traced in the paper. These often focus on the four-stage modelling approach, but some authors also criticise the "rational comprehensive" paradigmatical framework within which the use of four-stage computer models is situated. It is argued that the rational comprehensive model of thinking is less useful today, due to the increasing complexity of the transport planning exercise; the rejection by the public of the transport planner as "expert"; and the highly political nature of transport planning. Alternative approaches are needed in order to address the new types of problems which transport planners face. The use of one such alternative approach, the Soft Systems Methodology, is illustrated as suitable for investigating complex decision-making systems in transport planning. It is suggested that this method could be beneficial in other problematic transport planning situations where the rational comprehensive approaches prove inadequate. Finally, the paper briefly looks ahead and considers the implications of a changing policy environment to the training of transport planners in the future.  相似文献   

3.
Using four consecutive days of SITRAMP 2004 data from the Jakarta metropolitan area (JMA), Indonesia, this study examines the interactions between individuals’ activity-travel parameters, given the variability in their daily constraints, resources, land use and road network conditions. While there have been a significant number of studies into day-to-day variability in travel behaviour in developed countries, this issue is rarely examined in developing countries. The results show that some activity-travel parameter interactions are similar to those produced by travellers from developed countries, while others differ. Household and individual characteristics are the most significant variables influencing the interactions between activity-travel parameters. Different groups of travellers exhibit different trade-off mechanisms. Further analyses of the stability of activity-travel patterns across different days are also provided. Daily commuting time and regular work and study commitments heavily shape workers’ and students’ flexibility in arranging their travel time and out-of-home time budget, leading to more stable daily activity-travel patterns than non-workers.  相似文献   

4.
Abstract

For the last five years the technology factor (by which is meant both process and product innovation) has received renewed attention in the transport sector as society is confronted with new challenges. This leads to a call for change and transitions. Technology is considered as a potential answer to new needs and new problems, like the reduction of CO2 and the supply of alternative energy. It is important that there is a theoretical basis for the way of thinking on innovation and diffusion when it comes to technology dynamics. This paper, based on a literature study, addresses the question to what extent the theory of transition management can be considered as a new application of technology dynamics. The theory of technological innovations in the broad sense is analysed and applied to the transport sector.  相似文献   

5.
Abstract

Railways restructuring takes place under very different circumstances and with very different goals in Western Europe, Central and Eastern Europe, and Russia. There are some improvements in productivity associated with the reforms in the European Union (among others access to infrastructure and vertical separation). But they are not certain to be replicated following similar restructuring in transition economies, especially if one takes account of the much higher shadow price on government subsidies in the latter. The current and proposed reforms in the railways of Central and Eastern Europe and Russia are described in detail; the likely outcomes of reforms in the special economic, regulatory and legal environments of these countries are analysed; and an alternative proposal for restructuring in Russia is presented.  相似文献   

6.
7.
Suburban sprawl has been widely criticized for its contribution to auto dependence. Numerous studies have found that residents in suburban neighborhoods drive more and walk less than their counterparts in traditional environments. However, most studies confirm only an association between the built environment and travel behavior, and have yet to establish the predominant underlying causal link: whether neighborhood design independently influences travel behavior or whether preferences for travel options affect residential choice. That is, residential self-selection may be at work. A few studies have recently addressed the influence of self-selection. However, our understanding of the causality issue is still immature. To address this issue, this study took into account individuals’ self-selection by employing a quasi-longitudinal design and by controlling for residential preferences and travel attitudes. In particular, using data collected from 547 movers currently living in four traditional neighborhoods and four suburban neighborhoods in Northern California, we developed a structural equations model to investigate the relationships among changes in the built environment, changes in auto ownership, and changes in travel behavior. The results provide some encouragement that land-use policies designed to put residents closer to destinations and provide them with alternative transportation options will actually lead to less driving and more walking.
Susan L. HandyEmail:

Xinyu (Jason) Cao   is a research fellow in the Upper Great Plains Transportation Institute at North Dakota State University. His research interests include the influences of land use on travel and physical activity, and transportation planning. Patricia L. Mokhtarian   is a professor of Civil and Environmental Engineering, Chair of the interdisciplinary Transportation Technology and Policy graduate program, and Associate Director for Education of the Institute of Transportation Studies at the University of California, Davis. She specializes in the study of travel behavior. Susan L. Handy   is a professor in the Department of Environmental Science and Policy and Director of the Sustainable Transportation Center at the University of California, Davis. Her research interests center around the relationships between transportation and land use, particularly the impact of neighborhood design on travel behavior.  相似文献   

8.
截至2011年9月,中国客车统计信息网的数据显示:1~9月全国50家客车企业累计销售客车169231辆,累计增量11268辆,增幅为7.13%。庞大的销量下,我们很难想象,55年前的中国,甚至连一辆"made inChina"的客车都没有!建国前到建国初期,上海百老汇门口,偶尔能看见几辆略显破旧又摇摇欲坠的大客车缓缓开过,车尾的铜  相似文献   

9.
During the 1950s, the share of freight carried by railroads was similar and declining in both the United States and Europe. By 2000, the railroads’ share of freight (measured in ton–kilometers) had reached 38% in the United States while falling to 8% in Europe. This paper examines the reasons for the difference in rail’s share of freight in Europe and the United States. We find that almost 83% of the gap in 2000 is probably due to natural or inherent differences, principally geography, shipment distance, and commodity mix. However, 17% of the gap cannot be explained by these inherent differences and is presumably due to public policies including priority of passenger service, lack of interoperability at borders, service quality and rates, and incentives of the rail operators. We estimate that if that policy gap were closed, railroads’ share of freight in Europe would increase from 8% to 13%.
Mark FaganEmail:
  相似文献   

10.
Currently, two immersed tunnels are being constructed in Holland as part of a high speed railway link. Designing and building these two tunnels was a challenge due to a combination of factors: Technical specifications with small tolerances, which are never encountered before in Holland, poor soil conditions and a short construction period had to be managed.Some major aspects will be explained in this paper.  相似文献   

11.
C. A. Nash 《Transportation》1984,12(3):243-259
The 1974 Railways Act set British Rail (BR) the rather vague objective of providing a passenger service broadly comparable with that then existing within a given level of support. For the first few years under the Act, BR succeeded in operating within the financial constraints imposed, but only by considerable increases in charges and by negotiating wage settlements which implied declining real wages. From 1978 on, rising labour costs and reduction in traffic led to a rapidly developing crisis in BR's financial position.The position of each section of BR's business is discussed briefly. It is shown that the designation of some sectors as being purely commercial is inappropriate, since this means that benefits to users and to the community at large are ignored in decision-making. Similarly, the direction to maintain social passenger services at a given level means that finance and investment are concentrated unduly on preservation of the existing pattern of service, rather than on providing value for money. In both sectors, the likelihood is that in general fares are too high and services too frequent.At an operational level, the criterion of maximising the (weighted) volume of traffic carried is advocated as a practical way of choosing between alternative fare and service-level packages. More broadly based strategic studies would be needed to decide on the weights to be adopted, the level of finance to be made available, and the overall strategy.  相似文献   

12.
A sensitivity analysis of plausible errors in population, employment, fuel price, and income projections is conducted using the travel demand and emissions models of the Sacramento, CA, USA, region for their transportation plan. The results of the analyses indicate that plausible error ranges for household income and fuel prices are not a significant source of uncertainty with respect to the region's travel demand and emissions projections. However, plausible errors in population and employment projections (within approximately one standard deviation) may result in the region's transportation plan not meeting the conformity test for nitrogens of oxides (NOx) in the year 2005 (i.e., an approximately 16% probability). This outcome is also possible in the year 2015 but less likely (within approximately two standard deviations or a 2.5% probability). Errors in socioeconomic projections are only one of many sources of error in travel demand and emissions models. These results have several policy implications. First, regions like Sacramento that meet their conformity tests by a very small margin should rethink new highway investment and consider contingency transportation plans that incorporate more aggressive emissions reduction policies. Second, regional transportation planning agencies should conduct sensitivity analyses as part of their conformity analysis to make explicit significant uncertainties in the methods and to identify the probability of their transportation plan not conforming. Third, the US Environmental Protection Agency (EPA) should clarify the interpretation of “demonstrate” conformity of transportation plans; that is, specify the level of certainty that it considers a sufficient demonstration of conformity.  相似文献   

13.
It is commonly argued that, in order to meet increasing competition, public transport organizations and systems need to be market oriented. Even though the notion of market orientationhas not been explicitly addressed in public transport research, studies relevant to market orientation have been conducted. The aim of this paper is to introduce the concept of market orientation into the field of public transport, to review previous research into market orientation in public transport research, and to suggest directions for future research. Market orientation is defined as the generation and dissemination of market intelligence by organizations, as well as responses to it. The review suggests that previous academic research has focused on intelligence generation by developing and using models for measuring travel behaviour, stated preferences, perceived customer quality, and satisfaction. Studies of responsiveness have mainly addressed the physical improvements made in public transport organizations, which is also the primary concern of the industry research accounted for. There has been less research into the dissemination of market intelligence, the drivers of market orientation, the relations between the elements, and the overall concept of market orientation in public transport. It is thus concluded that future public transport research needs to address these issues.  相似文献   

14.
The aggregate dynamics of car ownership have overshadowed the dynamics of car ownership and availability at the personal and household level. These dynamics have only recently been investigated in more depth. This paper contributes to this work by probing a special data source, theLongitudinal Study (LS) produced by the Office of Population Censuses and Surveys, for the changes in household car availability.The paper describes the LS and explains its special format, as a Census-based ~1% sample of the population of England and Wales.The analysis focuses on the car availability dynamics of a number of groups defined by changes in their life cycle position. Special attention is given to those households where the LS member remains a dependent child throughout the study period.The results show that all studied household types increase and decrease their car holdings, but that there are patterns in this process, which vary from group to group. In particular, the size of the previous car fleet has a different influence on the current fleet size from life cycle group to life cycle group.The paper argues in its conclusion to incorporate these differentials into the further work on car ownership and car ownership change.The work reported here was performed, while the author was a staff member of the Centre for Transport Studies, Imperial College, London.  相似文献   

15.
<正>随着丝绸之路战略不断升级,有分析人士表示,相关概念股已经呈现出炒地图模式。如今,这一炒作风继续刮向"海上丝绸之路",预计相关区域板块的港口、海运等相关上市公司均将成为掘金洼地。今年以来,包括广东、福建、浙江、云南、广西、江苏等省区均公开表示,积极对接"海上丝绸之路"建设,港口建设成为规划建设中的重点。  相似文献   

16.
17.
Abstract

This paper seeks to reconstruct the organizational and ownership transformation involving Poland’s urban transport that companies passed through after 1990. Data collected from various sources (above all the Internet, including the Bulletins of Public Information) were used to establish the degree of advancement of the transformation processes. Despite the passage of nearly two decades since the new economic reforms were launched, the privatization processes involving enterprises of municipal origin are not well‐advanced. There is not a single private company among the organizers of urban transport. Instead, an absolute domination of budgetary‐sphere entities may be noted. Furthermore, there are seven transport municipal unions. Among the operators (carriers) public ownership remains dominant in the form of single‐person local authority companies, local government companies, municipal union ownerships, municipal companies as well as budgetary units. Privatization processes have encompassed fewer than 10% of all operators in the form of companies with foreign participation, workers’ companies and companies with Polish non‐public sector participation. Moreover, in 20 localities urban transport is supplied by multi‐trade municipal services enterprises (as of end‐2008). Thus, transformation processes, though started earlier than in the case of Poland’s State Road Transport coach companies, are much less advanced.  相似文献   

18.
We analyze the train types handled at a section station and the factors affecting the scheduling of the arrival–departure track operation, using the following conditions as our optimization goals: operating the arrival–departure tracks in accordance with a fixed operation scheme, and reducing the influence which the departing–receiving operations impose on shunting operations. We establish a 0–1 integer programming model for formulating a track operation plan. By applying modern sequencing theory, this is transformed into a fixed sequencing model of special parallel machines. We then design a heuristic algorithm to solve the model. Finally, the example of Yiyang railway station is used to verify the advantages of the model and the algorithm. A better operation plan is obtained using MATLAB 7.0 by applying the model and the algorithm provided in the paper, indicating the superiority of our study’s approach.  相似文献   

19.
Abstract

Based on a review of available data from a database on large‐scale transport infrastructure projects, this paper investigates the hypothesis that traffic forecasts for road links in Europe are geographically biased with underestimated traffic volumes in metropolitan areas and overestimated traffic volumes in remote regions. The present data do not support this hypothesis. Since previous studies have shown a strong tendency to overestimated forecasts of the number of passengers on new rail projects, it could be speculated that road planners are more skilful and/or honest than rail planners. However, during the period when the investigated projects were planned (up to the late 1980s), there were hardly any strong incentives for road planners to make biased forecasts in order to place their projects in a more flattering light. Future research might uncover whether the change from the ‘predict and provide’ paradigm to ‘predict and prevent’ occurring in some European countries in the 1990s has influenced the accuracy of road traffic forecasts in metropolitan areas.  相似文献   

20.
The development of behaviourally richer representations of the role of well-established and increasingly important influences on modal choice, such as trip time reliability and accounting for risk attitude and process rules, has moved forward at a fast pace in the context of automobile travel. In the public transport setting, such contributions have, with rare exception, not been considered. In this paper, we discuss and empirically illustrate the merits of advanced modelling developments aimed at improving our understanding of public transport choice, namely the inclusion of reliability in extended expected utility theoretic forms, to recognize risk attitude and perceptual conditioning, the consideration of passenger crowding and its inclusion in linear additive models, and the role of multiple heuristics in representing attribute processing as a way of conditioning modal choice. We illustrate the mechanics of introducing these behaviourally appealing extensions using a modal choice data set collected in Sydney.  相似文献   

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