Unraveling the relationship between trip chaining and mode choice: evidence from a multi-week travel diary

Abstract

Trip chaining (or tours) and mode choice are two critical factors influencing a variety of patterns of urban travel demand. This paper investigates the hierarchical relationship between these two sets of decisions including the influences of socio-demographic characteristics on them. It uses a 6-week travel diary collected in Thurgau, Switzerland, in 2003. The structural equation modeling technique is applied to identify the hierarchical relationship. Hierarchy and temporal consistency of the relationship is investigated separately for work versus non-work tours. It becomes clear that for work tours in weekdays, trip-chaining and mode choice decisions are simultaneous and remain consistent across the weeks. For non-work tours in weekdays, mode choice decisions precede trip-chaining decisions. However, for non-work tours in weekends, trip-chaining decisions precede mode choice decisions. A number of socioeconomic characteristics also play major roles in influencing the relationships. Results of the investigation challenge the traditional approach of modeling mode choice separately from activity-scheduling decisions.     

复合地基技术在北良港淤泥吹填区地基处理中的应用研究

介绍了复合地基技术的研究现状。结合在北良港淤泥吹填区建设一座轻钢结构火车铁路罩棚的工程实例,介绍了复合地基技术中的多种类型,如强夯置换碎石桩复合地基、刚性桩复合地基、夯实水泥桩等的计算方法,总结了设计、施工和检测等实际经验,并得出了相关的结论,以期为国内复合地基技术的研究提供一定的参考。     

A macroscopic taxi model for passenger demand,taxi utilization and level of services

In most urban areas taxi services are subject to various types of regulation such as entry restriction and price control. However, effective intervention depends on generating and using suitable information on the demand-supply equilibrium of the taxi market. This paper develops a simultaneous equation system of passenger demand, taxi utilization and level of services based on a taxi service situation found in the urban area of Hong Kong over the last ten years. A set of variables is introduced including number of licensed taxis, taxi fare, disposable income, occupied taxi journey time as exogenous variables and daily taxi passenger demand, passenger waiting time, taxi availability, taxi utilization and average taxi waiting time as endogenous variables. These variables are coupled together through a system of nonlinear simultaneous equations whose parameters are estimated from survey data. The simultaneous equation system can be used to obtain useful regulatory information to assist with the decisions concerning the restriction over the number of taxi licenses and the fixing of the taxi fare structure as well as a range of service quality control. This revised version was published online in June 2006 with corrections to the Cover Date.     

城市道路网饱和度模型及其应用

饱和度是反映道路交通状况的一个重要指标,也是评判道路服务水平的一个重要基准。目前所涉及到的饱和度仅指某一路段或交叉口的饱和度,且关于它的模型方法已比较成熟,但它仅是一个反映城市道路局部交通状况的量。文章从城市道路网整体出发,通过饱和度影响因素分析,探讨了道路网交通空间容量与路段通过能力、交通需求与路段交通量之间的相互关系,建立了城市道路网饱和度模型。算例分析表明,该模型简单、合理、实用。     

第三方物流企业约定作业能力控制研究

随着第三方物流企业应用高科技的速度不断加快以及模仿能力的普遍提高,企业竞争日趋激烈,准确核算和有效控制成本成为第三方物流企业提高管理水平、增强市场竞争优势的关键。成本控制的重点正逐渐向作业能力的控制与管理上转移。研究作业成本法在第三方物流企业作业能力成本控制中的应用,能够使企业根据未来物流服务的需求,确定未来期间最优的约定作业能力水平,从而为企业有效地控制约定作业能力成本提供科学的依据。     

降低沥青混合料加热成本的途径

分析了沥青混合料的生产过程,提出了集料、燃料、设备和生产过程等对加热成本的影响,为沥青混合料生产中节约能源提供了参考。     

道路拥挤定价下的公交收费模型研究

为了在执行道路拥挤定价政策的前提下制定公共交通的收费标准，提出可行的定价模型，根据交通行为科学的有关理论和方法，采用了两层规划技术建立了道路拥挤定价下的公交收费模型，上层规划为交通系统优化，下层规划为拥挤定价下的路网随机平衡问题。以广州市为研究对象，计算了拥挤定价下广州市公交线网的最优价格体系。研究结果表明：所提出的模型能够描述出行者和交通管理部门分别在出行和交通管理中的决策行为，较好地解释了用户平衡、路段路径流量和阻抗、交通需求、拥挤费、公交票价、出行成本等相互之间的逻辑关系。     

桥梁加固经济性评价

根据公路建设与经济发展的辨证关系,应用工程技术经济学的基本原理,对桥梁加固所引起的直接经济效益和间接经济效益进行了研究分析。桥梁加固产生的直接经济效益通过区分桥梁通行交通量的类型和车辆运输成本的变化进行了分析。利用桥梁加固工程的投资效果,建立了桥梁加固间接经济效益的计算方法。     

量、本、利分析法是经济活动分析好方法

在社会主义市场经济条件下,要作好经济管理工作,用量、本、利分析法开展经常性的经济活动分析,赢得市场竞争的主动权.     

Temporal disaggregation of travel demand for high resolution emissions inventories

The commonly used photochemical air quality model, the Urban Airshed Model (UAM), requires emission estimates with grid-based, hourly resolution. In contrast, travel demand models, used to simulate the travel activity model inputs for the transportation-related emissions estimation, typically only provide traffic volumes for a specific travel period (e.g. the a.m. and p.m. peak periods). A few transportation agencies have developed procedures to allocate period-based travel demand data into hourly emission inventories for regional grid cells. Because there was no theoretical framework for disaggregating period-based volumes to hourly volumes, application of these procedures frequently relied upon a single hypothetical hourly distribution of travel volumes. This study presents a new theoretical modeling framework that integrates traffic count data and travel demand model link volume estimates to derive intra-period hourly volume estimates by trip purpose. We propose a new interpretation of the model coefficients and define hourly allocation factors by trip purpose. These allocation factors can be used to disaggregate the travel demand model ‘period-based’ simulation volumes into hourly resolution, thereby improving grid-based, hourly emission estimates in the UAM.