城乡客运组织优化措施探讨

城乡客运是道路旅客运输的重要组成部分。文章从百色路网的发展趋势入手,分析了现阶段百色城乡客运存在的主要问题,提出了促进城乡客运组织优化的举措和建议。     

建议加快组建高速客运企业集团

高速客运不单纯是车速提高了的普通客运,而是在技术、经济、营运组织与管理等各个方面都与普通客运存在本质区别的新型旅客运输产业。根据我国高速客运的特点,提高经营管理效益既是运输行业发展的要求,又是充分发挥高速公路效用的重要环节。高速客运在优化     

走进陕西渭蒲高速

<正>一条极有可能成为陕西省建设速度最快的高速公路项目,并非人们想像得那么简单。在陕西省规划的"2367"高速公路网络中,渭南至蒲城高速公路是黄(龙)渭(南)联络线中的一段。在陕西省庞大的高速路网中,看似不起眼的53公里却是渭南市争取了12年的项目。     

高速公路客运如何发展

随着改革开放的深入以及经济发展对公路运输的需求,我国公路快速地向高等级发展.随之应运而生的高速公路客运以其快速、安全、经济、舒适的优势在综合运输体系中地位日趋重要.到2002年底,我国高速公路通车里程已达2.52万公里.据统计,当前投入高速公路客运的中、高挡客车已达到3 700多辆,虽然其发展的历史不长,但它已显示出勃勃生机和活力,给旅客运输带来了新的变化.如何使高速公路客运健康有序的发展是当前摆在交通行业面前的又一新的课题.     

承东启西 贯南通北——郑州国家公路客运枢纽强化中原城市群效应

郑州国家公路客运枢纽作为郑州市综合客运体系的建设平台,布局时充分考虑了与其他运输方式的客运站场布局相衔接,以减少旅客的换乘次数,提高综合运输效率。     

道路运输市场可持续发展战略思考

道路运输市场发展趋势 世界工业发达国家的各种运输方式中,道路客货运量与周转量的比重越来越大.我国高速公路和等级公路的兴起,也为发展道路运输带来新的机遇,近几年快速客运、快速货运的迅猛发展便是例子.     

对我国高速公路客运市场存在问题的思考

<正> 近几年来,随着国家对交通基础设施投入力度的加大,以高速公路为代表的高等级公路建设逐年加快,取得了突飞猛进的发展,高速公路客运应运而生并得以迅速发展,客运车辆的档次、数量、运行速度等大大提高。以高速公路为依托的高速公路客运的出现和发展,凭借其安全、舒适、方便、快捷的优势在几种旅客运输方式中处于重要地位,较好地适应了社会经济发展对公路客运质量提出的更高要求。     

公铁联运是大物流的必然选择

近年来，随着省级公路的改造、高速公路网络的逐步形成，道路运输业得以快速发展。路网建设的日趋完善带动了综合运输体系内各种运输方式之间的市场竞争，其中道路客货运与铁路客货运在客源与货源上的争夺更为激烈。     

营运里程图集要做"定盘星"

当道路运输成为服务范围最广泛,承担运量最大,运输组织最为灵活的运输形式时,当我国公路网建设如火如茶日新月异之时.如果没有一本准确全面、系统权威的营运里程图集,客运定价以何为准?货运运费以何为据?     

增强铁路客运竞争能力初探

<正> 近年来,随着高速公路的兴起、民航业的迅速发展,旅客运输市场竞争日益激烈,在竞争最为激烈的经济发达地区,铁路客运更是面临着失去市场份额的危险。公路对铁路的短途旅客运输形成强烈的冲击;在中长途客运市场,民航也与铁路展开了竞争。在如此严峻的态势下,铁路客运若想保持其在客运市场中应有的地位,占有和扩大市场份额,提高经济效益,就必须实现经营观念由传统计划经济向市场经济的转变,全面提高铁路客运的竞争能力。     

Survey of R&D in PRT systems

A survey of research and development in advanced transit has been made by Chalmers University of Technology in Gothenburg in cooperation with Trans21 in Boston. Summary findings are reported for fourteen academic research programs and ten development programs for PRT. An earlier version of this paper was presented at the International Conference of PRT and other Emerging Systems held in Minneapolis in 1996.     

The Impact of Container Type Diversification on Regional British Port Development Strategies

Abstract

Despite a concentration of container traffic in the southeast of the UK over the last few decades, regional ports are attempting new development strategies to capture or retain specific traffic segments. These include intra-European short-sea traffic and a potentially increasing feeder market. These trends are reflected in the movement of different container types, which result in a number of planning challenges related to changing infrastructural and operational requirements. This paper uses highly disaggregated data on container type movements to address three issues that can inform these planning challenges. First, the imbalance of trade resulting in empty container repositioning; second, the requirement for gauge-cleared rail routes to cater for the increasing proportion of high-cube containers; and third, the specialisation of European short-sea traffic at secondary UK ports. The results reveal the disproportionate repositioning of empty containers at Scottish ports and the importance of 45?ft, high-cube and pallet-wide containers at regional ports, highlighting their focus on intra-European short-sea traffic and raising difficulties relating to their lower quality of landside infrastructure (particularly rail) in comparison to the large south-eastern ports. The potential repercussions on hinterland infrastructure development raise questions about both public and private sector responses to regional port development.     

Modular route bus design – A method of meeting transport operation and vehicle manufacturing requirements

This research examines the problem of route bus specification and vehicle manufacturability. In order for bus operators to provide transport services, a range of vehicle configurations must be available from bus manufacturers, generating variety which has a negative impact on the manufacturing process. Larger part inventories, uncontrolled labour tasks and more troublesome maintenance are known impacts of this variety. This research identifies the functional necessities in route bus interior design and reduces the problems in bus manufacture and operation caused by specification diversity by proposing a modularised system of bus design. In particular, it makes recommendations as to how bus configuration should be carried out, ensuring an optimum mix of operational and manufacturing needs:

• 1.Determine user needs before the bus specification process.
• 2.Designs to be developed by the manufacturer in response to user needs.
• 3.This design should be standardised where possible, as suggested by the user needs.
• 4.Where user needs dictate product variations, apply a mass customisation approach to accommodate these needs.

The recommendations are communicated in design proposals for a modular bus interior, demonstrated by four cases designed to meet the present status quo of bus interior design and predictions for the future of the field.     

Determinants of modal choice in freight transport

In the next few years, exciting developments in the field of freight transport are likely to occur. The Channel Tunnel will be perceived as giving railways much greater distance of operation, compared to the current train ferry to/from Great Britain. The further development of swap-body technology will allow easier modal transfer and the creation, in 1992, of a single market in Europe will transform the pattern of trade. All of these are likely to have significant impacts on modal choice, and hence modal split, in freight transport. Reappraisal by many firms of the modes of transport used is likely but will it result in a net transfer of freight from road to rail and, if so, to what extent? To answer such questions, an accurate and reliable method of predicting modal split is required. Research in the past has concentrated on the development of modal split models based on generalised costs. These fail to explain adequately the prevalence of road freight in the UK. From surveys of freight managers within industry, it is clear that models to date rely too heavily on the economic cost factor and too little on behavioural factors (Jeffs 1985). This paper derives from a recent study of freight transport modal choice from the standpoint of the transport decision-maker within the firm. It attempts to shed light on the actual parameters which should be incorporated into a modal split model. Many variables appear to exert an influence on modal choice decision-making process. However, it is possible to categorise them into six main groups, namely: customer-requirements; product-characteristics; company structure/organisation; government interventions; available transport facilities; and perceptions of the decision-maker him/herself. It is the interactions and inter-relationships between these which ultimately determine freight modal split. This study has shown that the relationship between the outcome of the transport decision process and the values of particular determinants of modal split is not straight-forward, due to the complexity and variety of interactions involved. Perhaps one of the main reasons for researchers' failure hitherto to develop a successful modal-split model has been the preoccupation with techniques that rely on the development of common metric (e.g. generalised cost), which has led to the exclusion of some important explanatory variables along quite different dimensions. Another important issue concerns the appropriate level of aggregation. In order not to reduce the explanatory power of the key variables, it is important to work at a disaggregate level, although this does make substantial demands on data. The use of factor analysis enables both the aggregation of information without loss of behavioural reality and the specification of variables in terms of a common metric. In conclusion, freight transport has usually been examined within too narrow a framework. It must be placed firmly within the context of the total industrial process. The demand for freight transport is directly influenced by the level, composition and geographical distribution of production and consumption activities. Freight flows are complex and so it is highly unlikely that a universal mode-choice model can ever be developed. Future research should, therefore, be directed towards developing partial models in response to specific needs of those involved in decision-taking in the freight sector.     

Optimization of bus stop locations for improving transit accessibility

A mathematical model is developed in this paper to improve the accessibility of a bus service. To formulate the optimization model, a segment of a bus route is given, on which a number of demand entry points are distributed realistically. The objective total cost function (i.e. the sum of supplier and user costs) is minimized by optimizing the number and locations of stops, subject to non‐additive users' value of time. A numerical example is designed to demonstrate the effectiveness of the method thus developed to optimize the bus stop location problem. The sensitivity of the total cost to various parameters (e.g. value of users' time, access speed, and demand density) and the effect of the parameters on the optimal stop locations are analyzed and discussed.     

Productive efficiency and ownership of urban bus services

The established ownership mix of urban bus operations in Australia provides a unique opportunity to investigate the productivity differences between public and private bus service supply. Using duality theory in economics which links economic indices of factor productivity to the cost structure of a firm, we develop empirical measures of total and partial productivity of inputs, and adjust the differences for the effects of ownership status and operating environment. The evidence supports the notion that private supply of public passenger transport in general has performed more efficiently in the past than public supply, although the differences in productivity need not continue in the future.     

管道风险分析指数评分法中分值调整初探

管道风险分析指数评分法中重要步骤之一就是确定影响管道事故因素的权重,各个管道风险因素在整个管道事故中所占的权重是不相同的。针对目前管道风险分析指数评分法基本假设之一（各因素的分值范围都是0～100分）,为了更加客观、准确、合理地反映各个风险因素对于管道事故的影响程度,提出并论述了依据层次分析法的数学逻辑性进行综合计算得出管道风险因素的权重,然后对评分法中各个因素的最高分值,根据其权重不同进行相应调整,从而增强评价者对风险因素的认识和评判能力,提高管道风险评价结果的准确性。     

A century of evolution of the accessibility concept

The concept of accessibility has acquired numerous meanings along multiple dimensions during the century of its evolution. This essay argues for the salience of two dimensions: application-based and definition-based. In its application, accessibility has incorporated positive and normative dimensions which have varied in prominence over time. In its definition, accessibility has varied between a mode of evaluation incorporating measured mobility and proximity, on the one hand, and a predefined market basket of urbanist improvements to transportation and land use systems, on the other. Advocates of the accessibility shift should emphasize both the measured approach to accessibility and accessibility’s normative side.     

天然气站往复式压缩机活塞失效分析

针对天然气站往复式压缩机活塞的断裂事故,运用失效分析方法,开展了活塞断口扫描电镜分析、能谱和金相分析。根据断口形貌的电镜和金相观察结果,结合理论知识,分析确定了该活塞发生断裂事故的主要原因,即在特定工况下该活塞的材料缺陷是造成断裂的主要因素。