Estimation of origin‐destination matrices for a multimodal public transit network

This paper presents a procedure for the estimation of origin‐destination (O‐D) matrices for a multimodal public transit network. The system consists of a number of favored public transit modes that are obtained from a modal split process in a traditional four‐step transportation model. The demand of each favored mode is assigned to the multimodal network, which is comprised of a set of connected links of different public transit modes. An entropy maximization procedure is proposed to simultaneously estimate the O‐D demand matrices of all favored modes, which are consistent with target data sets such as the boarding counts and line segment flows that are observed directly in the network. A case study of the Hong Kong multimodal transit network is used to demonstrate the effectiveness of the proposed methodology.     

Total cost analysis: An alternative to benefit-cost analysis in evaluating transportation alternatives

This paper explains the theory in support of total cost analysis (TCA) to compare transportation system alternatives. The full costs of each alternative are first aggregated, including travel time costs and monetizable environmental and social costs. Many costs which are considered on the benefits side of the equation in benefit-cost analysis (BCA) as "cost savings" are brought over to the costs side. Total cost differences among alternatives are then traded off against their estimated non-monetized benefits or impacts, just as a consumer trades off product quality against cost before deciding which product he or she will buy. One advantage of TCA over traditional BCA is that the concept of "total cost" is more easily understood by the public and by political decision-makers than BCA concepts such as "net present worth", "benefit-cost ratio" and "internal rate of return". A second advantage is that there is no suggestion that all "benefits" have been considered; decision-makers are free to use their own value judgements to trade off total cost against non-monetizable social, environmental and economic impacts, just as they trade off quality and convenience against cost when purchasing goods and services in their roles as consumers. The TCA approach is demonstrated in this paper through a case study of two systemwide alternatives for the Baltimore, MD urban area.     

武汉港阳逻港区多式联运发展思路

多式联运能够充分发挥各种运输方式的综合优势,对于推动物流业降本增效、完善现代综合交通运输体系具有积极意义。武汉港阳逻港区具备发展多式联运的各项要素,但缺乏对多式联运发展的系统性规划,港区多式联运发展相对滞后,综合交通优势尚未有效发挥。通过总结典型案例的发展经验,结合港区内外部综合因素,思考港区多式联运发展思路,探讨港区多式联运的布局规划以及综合服务的提升,并提出相关建议。     

Intermodal transport in freight distribution: a literature review

There has been significant growth in research on intermodal transport in freight distribution since the 1990s. Differentiating itself from previously published literature reviews, this paper evaluates the current state of this research using Systematic Literature Review methodology. The complementary aims are: (a) to identify the research lines developed and to propose a criterion for classifying the literature, and (b) to discuss the empirical evidence that identifies existing interrelationships. The analysis has enabled three main lines of research to be identified. The first research line, basic principles of intermodal transport, groups together works related to the definition of intermodal transport and the results obtained using this transportation system. The second, improvements to the way that intermodal transport systems work, frames elements and variables that impact intermodal transport systems’ logistics efficiency, such as quality of service, information and communication systems, and freight planning and linkages among system operators to provide an adequate service. Finally, the third line, intermodal transport system modelling, identifies the main variables used to optimise these transport systems, the different focuses and approaches used in modelling, and the advantages and disadvantages of each focus. These research lines take in more specific sublines that incorporate articles that develop related research questions. Lastly, the discussion of the content of each of these research sublines enables us to identify gaps in the literature and comment on directions for future research.     

Multimodal,multiclass stochastic dynamic traffic assignment for evaluating information provision strategies

A multimodal, multiclass stochastic dynamic traffic assignment model was developed to evaluate pre‐trip and enroute travel information provision strategies. Three different information strategies were examined: user optimum [UO], system optimum [SO] and mixed optimum [MO]. These information provision strategies were analyzed based on the levels of traffic congestion and market penetration rate for the information equipment. Only two modes, bus and car, were used for evaluating and calculating the modal split ratio. Several scenarios were analyzed using day‐to‐day and within day dynamic models. From the results analyzed, it was found that when a traffic manager provides information for drivers using the UO strategy and drivers follow the provided information absolutely, the total travel time may increases over the case with no information. Such worsening occurs when drivers switch their routes and face traffic congestion on the alternative route. This phenomenon is the 'Braess Paradox'.     

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在集装箱多式联运系统中,内陆运输方式和路径的选择,对集装箱门到门运输过程的运输效果产生很大的影响.为更合理地组织多式联运,本文在充分考虑集装箱内陆运输路径因素的同时,研究集装箱多式联运在运输方式转换过程中节点作业随机特征对运输方式和路径选择的影响.以总成本最小为目标,建立带有时间约束的混合整数规划模型,通过图形变换,将问题转化为节点作业带有随机特征和运输时间约束的最短路模型.通过实例验证并对结果进行分析,求得的路径在成本和时间方面较合理,具有可操作性,可以成为多式联运路径选择的决策参考.     

基于网络的高职英语自主学习多模态环境构建

本文探讨了在网络技术不断发展的背景下,如何建立网络的多模态环境,从多个方面给予高职学生不同的学习体验,以提高高职英语自主学习的效果,最后提出了一种基于网络多模态英语自主学习模型。     

运输需求预测计算机辅助系统研究

在改进传统四阶段预测方法的基础上,设计预测系统的总体结构和流程,介绍供需平衡调整方法,着重阐述系统在多方式运输网络拓扑结构描述方法、广义费用的构成和路径选择模型的改进3方面的工作,并开发了相应的计算机软件系统。在含拟建京沪客运专线在内的多方式运输网的基础上建立研究案例,采用"有无项目"对比的方法,使用所开发的软件系统分析了对比方案中京沪沿线相关区域运输需求的变化。     

集装箱公铁联运的费用加权最短路计算机算法

结合公铁联运过程中承运、中转和交付的3个环节,借鉴Dijkstra标号算法思路,提出一种多阶段定向搜索的标号算法解决集装箱公铁联运费用最短路问题。该算法考虑路网中铁路线路和公路线路的区别,引入了集装箱办理站选择集的概念,并考虑集装箱办理站的中转费用。给出若干计算实例,编程计算的结果证明该算法具有实际意义和高可靠性。     

Policy innovations of the US intermodal surface transportation efficiency act and clean air act amendments

In combination, the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) and the Clean Air Act Amendments of 1990 (CAAA) are innovative and aggressive efforts to move US cities toward integrated transportation and air quality planning. Under these complementary laws, air quality has become a major national transportation goal. In areas with serious air pollution, air quality will be a major consideration in determining the future shape of urban transportation.This paper considers how the CAAA and ISTEA combine to provide an innovative national policy approach of interest to countries seeking to encourage sustainable development in urban centers. The CAAA mandates measurable and enforceable air quality targets. Nation-wide standards are set for acceptable levels of carbon monoxide, ground level ozone, and small particulates. ISTEA includes directions for transportation planners and decision-makers to follow to reach air quality and other goals — transportation planning must emphasize system efficiency, and for cities with severe air pollution, transportation projects are expected to contribute to cleaner air. Each urban area has flexibility in how it applies this framework to reflect its priorities and solve its problems. Strict federal sanctions provide incentives for compliance with both laws.Enactment of these laws has produced a period of transition and uncertainty as well as of challenge and opportunity for planners and elected officials. The next several years, the US will provide one national laboratory and over 100 different urban laboratories for innovative approaches to integrate transportation and environmental policies to resolve major urban problems.Abbreviations CAAA Clean Air Act Amendments of 1990 - CO Carbon monoxide - ECO Employee Commute Option - EPA US Environmental Protection Agency - HC Transportation hydrocarbons - I/M Inspections and maintenance program - ISTEA Intermodal Surface Transportation Efficiency Act of 1991 - MPO Metropolitan planning organizations - NO_x Nitrogen oxides - PPM Parts per million - PM₁₀ Small particulate matter - SIP State Implementation Plan - TIP Transportation Improvement Program - TCM Transportation control measures - VMT Vehicle miles traveled