Experimental design influences on stated choice outputs: An empirical study in air travel choice

Discrete choice experiments are conducted in the transport field to obtain data for investigating travel behaviour and derived measures such as the value of travel time savings. The multinomial logit (MNL) and other more advanced discrete choice models (e.g., the mixed MNL model) have often been estimated on data from stated choice experiments and applied for planning and policy purposes. Determining efficient underlying experimental designs for these studies has become an increasingly important stream of research, in which the objective is to generate stated choice tasks that maximize the collected information, yielding more reliable parameter estimates. These theoretical advances have not been rigorously tested in practice, such that claims on whether the theoretical efficiency gains translate into practice cannot be made. Using an extensive empirical study of air travel choice behaviour, this paper presents for the first time results of different stated choice experimental design approaches, in which respective estimation results are compared. We show that D-efficient designs keep their promise in lowering standard errors in estimating, thereby requiring smaller sample sizes, ceteris paribus, compared to a more traditional orthogonal design. The parameter estimates found using an orthogonal design or an efficient design turn out to be statistically different in several cases, mainly attributed to more or less dominant alternatives existing in the orthogonal design. Furthermore, we found that small designs with a limited number of choice tasks performs just as good (or even better) than a large design. Finally, we show that theoretically predicted sample sizes using the so-called S-estimates provide a good lower bound. This paper will enable practitioners in better understanding the potential benefits of efficient designs, and enables policy makers to make decisions based on more reliable parameter estimates.     

Timetable-based operation in urban transport: Run-time optimisation and improvements in the operating process

Urban public transit provides an efficient means of mobility and helps support social development and environmental preservation. To avoid loss of ridership, transit authorities have focussed on improving the punctuality of routes that operate using timetables. This paper presents a new approach to generating run-time values that is based on analytical development and micro simulations. The work utilizes previous research (described herein) and the experience acquired by Transports Metropolitans de Barcelona (TMB) in operating bus routes based on timetables. Using a sample of historical data, the method used for generating run-time values consists of the following steps: purging and screening atypical trips, based on the consideration of confidence intervals for median trips; segmenting the day into time bands based on the introduction of a new hierarchical classification algorithm; creating initial run-time values based on criteria derived from statistical analysis; adjusting and validating initial run-time values using micro simulations; and evaluating incident-recovery times at the end of trips in order to guarantee the punctual departure of the next trip in the vehicle schedule. To favour service improvement, we also introduced certain indicators that can identify the root causes of non-compliance. As a final step, in order to ensure the applicability and use of the model, we promoted the development of our model within the framework of the HASTUS™ software solution.     

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城市公共交通乘客出行成本的量化研究,对于科学合理地评价公共交通系统的社会效益意义重大,而出行时间价值是进行乘客出行成本估计的一个重要环节. 本文以北京市市区居民SP调查数据为依托,通过分析公共交通出行时间价值的影响因素,选取Logit模型为基础模型,引入“出行者收入”作为模型新增变量,并针对工作商务、社会娱乐两种出行目的在不同换乘情况下出行时间价值模型进行参数标定,建立了基于SP调查数据的改进型时间价值求解模型,并计算得到北京市公共交通出行者在不同出行目的和有无换乘情况下的换乘时间价值、候车时间价值以及运行时间价值. 研究发现,工作商务出行目的出行时间价值普遍高于社会娱乐的出行时间价值,出行者在不同出行目的和有无换乘情况下的候车时间价值,大于换乘时间价值以及运行时间价值,并且有换乘情况下的候车时间价值大于无换乘情况下的候车时间价值.     

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在城市轨道交通的线路网络形成、实行一票换乘并伴随投资主体多元化时,需要建立公平公正的票务清分机制,本文提出一个基于乘客旅行实际时间分布计算各路径上乘客比例的新方法.根据交通卡中的进出站的时间记录,计算出在一段时间内在一对出入站之间完成旅行的所有乘客的时间分布,以这个分布为依据计算在这段时间里各路径上的乘客比例.采用数值模拟的方法在一对有两条有效路径的出入站间产生乘客旅行时间的数据,然后根据这些数据进行客流比例计算.结果表明,即使两条路径的运营时间差异很小也能实现较准确的比例划分,这种动态计算客流分布的方法能更准确地反映实际客流分布.     

温拌沥青混合料马歇尔变温变击实功设计方法

为了建立温拌沥青混合料组成设计方法,在不同温度和击实次数下进行了AC-13C温拌沥青混合料的马歇尔击实试验,分析了温拌沥青混合料体积特性。分析结果表明：随着击实温度的降低和击实次数的减少,温拌沥青混合料的空隙率和矿料间隙率增大,沥青饱和度降低;与热拌沥青混合料相比,温拌沥青混合料中沥青被集料吸收的含量（质量分数）、有效...     

Modeling Correlation of Family Holiday Activities Based on Structural Equation Model

Previous researches in activities-decision have more in-depth study in context of individuals, while less work has been done within household activity decisions. The structural equation model is applied to analyze the relationship of three household activity categories on holiday using data from 2009 Jinan travel survey. Six attributes were first chosen as exogenous variables for the structural equation model. Meanwhile, six activity characteristic indexes were selected as endogenous variables including activity duration time and activity times in three kinds of activity, hereby Subsistence activity, maintenance activity and discretionary activity. respectively. Then, the paper attempted to discuss the correlation of all types of activities behavior through analyzing not only the influence of household economics and family members factors on activity but the correlation of holiday activities. The research shows that complex relationships among composition of the family, economic status, and activities-decision can be captured by the structural equation model structure. Specifically, the results show that flexibility of three categories activities will affect the activities of decision-making.     

论增强德育的时代性

德育的时代性表现为德育和时代的双向互动作用,但时代决定德育的命运,因此增强德育的时代性首先应准确定位德育的时代,通过对当前社会特征的分析和德育性质的考查,把德育的时代定位于中国特色社会主义是理性且科学的,同时以职业生涯规划为载体,全面推进当代中国马克思主义的学习与运用,为中国特色社会主义建设提供强大的精神动力,以切实增强德育的时代性。     

交通拥堵反思

通过对交通拥堵进行反思,认为交通拥堵是充满活力的成功城市的伴生品,应从不同角度考虑拥堵问题.提出了十项有别于传统观点的提议,主要包括:机动性至关重要,交通拥堵是社会、经济活力的象征;道路扩容效果短暂,并会诱发潜在需求,但仍可带来一定的社会、经济效益;土地使用对出行行为的改变需要长期的努力;紧凑型发展会加剧交通拥堵;降低...     

城市土地利用特征对居民出行方式的影响——以深圳市为例

为缓解日益严重的城市交通问题、优化居民出行方式,有必要研究城市土地利用与交通系统的协调问题.以深圳市为例,应用多元Logit模型(MNL模型),纳入城市土地利用变量与出行者的家庭、社会、经济等变量,分析其对居民工作与非工作出行方式的影响.研究结果表明,出行起点的城市区位是影响居民出行方式的重要因素之一.相对于组团中心和...     

基于WebGIS的铁路旅客辅助决策系统的研究与开发

以旅客出行和换乘中转站的选择及优化作为实现目标,研究了针对旅客不同出行需求的查询算法,开发出基于WebGIS的铁路旅客出行辅助决策系统.系统为旅客出行决策提供综合查询信息,将最优线路以直观的方式显示出来,实现乘车线路的交互式查询和地理信息系统的实时衔接,后台决策软件综合考虑线路状况,实时更新铁路客运时刻表数据库,给出最优乘车路径选择.