On the semantic scale problem in stated preference rating experiments

Stated preference (SP) rating experiments are easy to design and conduct. Furthermore, they constitute a generalisation of SP choice experiments in terms of the information about preferences that can be achieved. However, its results are sensitive to the numerical values assigned by the analyst to the semantic scale used by individuals to express their preferences. We consider this problem in depth using a variety of statistical techniques, including ordinal probit and a novel optimal scale linear regression approach.     

Modelling route choice behaviour in multi-modal transport networks

The paper presents new findings on the influence of multi-modal trip attributes on the quality and competitiveness of inter-urban multi-modal train alternatives. The analysis covers the entire trip from origin to destination, including access and egress legs to and from the train network. The focus is on preferences for different feeder modes, railway station types and train service types as well as on the relative influence of time elements and transfer penalties. Data from dedicated surveys are used including individual objective choice sets of 235 multi-modal homebound trips in which train is the main transport mode. The observed trips have origins and destinations within the Rotterdam–Dordrecht region in The Netherlands with an average total trip time of 50 minutes. Hierarchical Nested Logit models are estimated to take account of unobserved similarities between alternatives at the home-end and the activity-end of the trip respectively, resulting in two-level nesting structures which differentiate between intercity (IC) and non-intercity railway station types at the upper level and between transit and private access modes at the lower level. In order to reflect the multi-dimensional structure of the data a more advanced so-called Multi-Nested GEV model according to the Principles of Differentiation has been estimated which significantly improves the explanatory power and stresses the importance of the home-end of the multi-modal trip.     

Rural mobility and mode choice: Evidence from the 2001 National Household Travel Survey

This article uses data from the 2001 National Household Travel Survey (NHTS) to compare travel behavior in rural and urban areas of the U.S. As expected, the car is the overwhelmingly dominant mode of travel. Over 97% of rural households own at least one car vs. 92% of urban households; 91% of trips are made by car in rural areas vs. 86% in urban areas. Regardless of age, income, and race, almost everyone in rural areas relies on the private car for most travel needs. Mobility levels in rural areas are generally higher than in urban areas. That results from the more dispersed residences and activity sites in rural areas, which increase trip distances and force reliance on the car. Somewhat surprisingly, the rural elderly and poor are considerably more mobile than their urban counterparts, and their mobility deficit compared to the rural population average is strikingly less than for the urban elderly and poor compared to the urban average. Data limitations prevented a measurement of accessibility, however, and it seems likely that rural areas, by their very nature, are less accessible than urban areas, especially for the small percentage of car-less poor and elderly households.     

Flexible substitution patterns in models of mode and time of day choice: new evidence from the UK and the Netherlands

Modelling the temporal response of travellers to transport policy interventions has rapidly emerged as a major issue in many practical transport planning studies and is recognised to hold particular challenges. The importance of congestion and its variation over the day, together with the emergence of time-dependent road user charging as a policy tool, emphasise the need to understand whether and how travellers will change the timing of their journeys. For practical planning studies, analysts face a major issue of relating temporal changes to other behavioural changes that are likely to result from policy or exogenous changes. In particular, the relative sensitivity of time and mode switching has been difficult to resolve. This paper describes a study undertaken to determine the relative sensitivity of mode and time of day choice to changes in travel times and costs and to investigate whether evidence exists of varying magnitudes of unobservable influences in time of day switching. The study draws on data from three related stated preference studies undertaken over the past decade in the United Kingdom and the Netherlands and uses error components logit models to investigate the patterns of substitution between mode and time of day alternatives. It is concluded that the magnitude of unobserved influences on time switching depends significantly on the magnitudes of the time switches considered. With time periods of the magnitude generally represented in practical modelling, i.e. peak periods of 2–3 hours, time switching is generally more sensitive in these data than mode switching. However, the context of the modelling and the extent to which relevant variables can be measured will strongly influence these results.     

基于合同网的IRP问题协商机制研究

针对存贮路径问题，采用多代理系统技术，将问题功能实体抽象成Agent，从而构建了基于多代理系统的体系结构，通过基于合同网的协商机制分析，探讨了补货任务与配送车辆之间智能分配策略，并以实例进行了说明。     

出行方式决策的随机效用模型研究

基于随机效用理论的多项logit(MNL)模型常用来解决多方案选择问题。介绍了该模型进行个体出行模式决策分析的方法,建立了线性效用函数假设条件下,个体出行模式选择概率与模式特性变量之间的近似线性关系。最后通过一个两模式决策分析的简例说明该模型的用法及灵敏度分析方法。     

基于并行遗传神经网络算法的限制搜索区域最优路径方法

在大规模路网的路径诱导中，研究了基于神经网络的交通信息实时预测方法，构造了具有时变性的路阻矩阵，解决了传统静态路阻存在的局限性问题；探讨了基于并行遗传算法的最优路径求解问题，给出了相应的遗传、变异算子和群体更新方式，提出了矩形限制搜索区域方法，降低了并行遗传算法的搜索范围，解决了遗传算法在大规模路网中求解最优路径时存在的实时性差、收敛速度慢等问题；仿真实验表明该方法满足大规模路网路径诱导的准确性、实时性和快速性要求。     

先进的旅行者信息系统对出行者选择行为的影响研究

目前研究先进的旅行者信息系统对出行者选择行为的影响主要集中在对路径选择行为的影响上,而忽略了对出行者出行终点和交通方式选择的影响。假定路网中的出行者一部分装有信息装置,另一部分没有装信息装置,利用离散选择理论中的层次选择结构模型和交通规划理论中的随机均衡方法,研究了先进的旅行者信息系统对出行者终点选择,方式分担和路径选择行为的综合影响,建立了一个与网络均衡条件等价的数学规划模型,设计了模型的求解算法,并用一算例分析了市场渗透率和信息质量对出行者选择行为的影响。     

基于路线优选的公交线网优化设计方法研究

传统的公交线网优化设计或基于经验或基于评价结果,需要规划者有较丰富的专业背景知识,但不能起到良好的决策支持作用.基于现有的路径生成与公交客流分配方法,总结并提出了一套完整的基于路线优选的方案生成型公交线网优化设计方法,介绍了该方法的实现流程、应用该方法的关键模型及算法,并通过算例验证了这种基于路线优选方法的公交线网优化设计的可行性.