Testing port choice models using physical and monetary data: a comparative case study for the Spanish container trades

ABSTRACT

Transport costs are useful explanatory variables in port choice research. Nevertheless, the availability of such information usually poses a problem. Thus, the formulation of an alternative approach, to be used as a proxy of these variables, would be desirable. The objective of this study is to improve the analysis of container port choice using logit models by adopting physical non-monetary indicators based on maritime distance and ship size. The statistical tests of logit models on port choice using these new variables are compared with the result of using cost variables for the same data set of choice positions. The statistical outcome is good and allows us to present this new approach as a contribution to the literature on port choice modeling.     

城市轨道交通在机场枢纽集疏运体系中 的竞争力分析

对比分析国内外机场集疏运体系的交通方式结构可以发现,我国机场集疏 运体系中城市轨道交通所承担的运输份额远低于其他国家.本文分析了影响机场集疏 运体系中各交通方式竞争力的主要因素,构建了城市轨道交通竞争力的多元 Logit 模 型.以首都机场为研究案例,验证了本文模型的正确性与有效性.最后提出了提高机场 城市轨道交通系统竞争力的措施,通过灵敏度分析得出了各项措施对城市轨道交通 系统市场份额的影响.     

基于 BL 模型的居民小汽车出行行为研究

本文采用离散选择模型,对采集到的4071份调查问卷所得到的居民出行情况进行分析,建立了BL 模型,定量分析影响小汽车出行行为的影响因素.分析结果表明:家庭月收入、出行距离和是否拥有驾照对小汽车出行的影响最大,出行费用、出行时间等因素对是否选择小汽车出行也有显著影响,而年龄、出行目的等因素则对是否选择小汽车出行的影响不显著.随后,对小汽车出行概率影响显著的因素做了敏感性分析,模型检验的结果说明该模型具有较好的精度.     

土地开发利用和社会经济发展对家庭汽车拥有量的影响——沙特阿拉伯利雅得市和澳大利亚墨尔本市的比较(英文)

汽车保有量取决于城市的土地开发模式。在一定时期内,一个地区的就业、住房、休闲、教育和购物条件以及家庭成员的年龄、性别、收入和家庭规模都会影响到人们对出行目的地和出行方式的选择,而家庭住房位置的影响则是长期的。应用沙特阿拉伯利雅得和澳大利亚墨尔本两座城市数据,分析了城市总体用地水平和人均水平、家庭人口及其距离工作地点的路程等对家庭汽车拥有量的影响,建立了家庭汽车拥有量多项式逻辑模型。模型表明,城市扩张是影响家庭汽车拥有量的主要因素,利雅得市家庭汽车拥有量在2辆以上,而墨尔本市不少于1辆。     

基于二项logit的无水港选址影响因素分析及预测

采用二项logit模型求解无水港的选址问题。首先,识别影响无水港选址的关键性因素;其次,利用logit概率可得到某一城市被选做为无水港的可能性大小。同时,候选城市可根据二项logit权重为自己评估,扬长辟短,使得自身优于临近城市被选做为无水港的概率增大。     

基于出行链的有车家庭假日出行方式组合研究

为了研究有车家庭居民出行链与出行方式组合的影响关系,将出行链划分为5种类型,并将出行链属性分为4类.利用2009年济南市居民出行调查数据,用基于多项logit模型的基本理论与建模方法,对影响城市居民出行方式组合的因素进行了研究,重点分析了出行链各项属性对居民出行方式选择的影响.模型分析结果表明,出行链中往返行程数量、出行链模式、出行链时间、出行链费用对于出行者选择何种出行方式组合有显著的影响.出行链复杂性的增加并不会直接导致私家车出行的增加,而随着往返行程数的增加会导致单一非私家车出行效用的显著增加.     

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为提高交通规划与决策质量,有必要妥善处理交通调查无回答问题. 但是在相关研究中尤其在发展中国家此问题常被忽视. 本文统计分析了发展中城市居民出行调查中项目无回答的缺失模式,进一步分析项目无回答作为模型缺失数据对基于期望最大化的数据修补的多项Logit集计的出行方式选择模型的影响. 选择三个发展中城市代表调查无回答的三个等级做案例分析. 首先,根据项目无回答缺失模式,利用Pearson开方检验得出重要的出行者社会经济属性和出行背景因素. 其次,利用基于缺失模式分析的期望最大化估计,处理缺失数据得到无偏数据集作为基准. 此外,利用独立样本的T检验检验了零假设,即有无期望最大化估计情况下的模型参数估计是相同的. 用基于R平方系数的内在效度检验计算估计情况下的模型预测偏差. 最后,考虑缺失数据的影响,评估一个重要的指标——出行时间价值. 结果表明,在发展中城市,问卷回答者和不回答者的社会经济背景存在很大差异. 缺失率和缺失模式均对出行方式选择模型的参数和预测精度有很大影响. 考虑缺失模式的出行时间价值计算表明, 项目无回答对出行时间价值的影响被过高估计了.     

Effects of Item Nonresponses on the Performance of Travel Mode Choice Models for Developing Cities: A Comparative Analysis

To enhance the quality of transportation planning and policy making, it is necessary to properly deal with the nonresponse issues in transport surveys. However, such nonresponse issues especially in developing countries have been ignored in literature. This paper first statistically identifies the missing patterns of item nonresponse (INR) in person trip survey data collected in developing cities and then analyzes the effects of INR on the performance of travel mode choice model (an aggregated multinomial logit model) based on expectation-maximization (EM) imputation method. As a case study, three developing cities representing three levels of INR are analyzed as follow. Firstly, the statistically significant social-economic attributes of trip makers and trip-context factors are identified with respect to INR in the missing pattern analysis by using Chi-Square test method. Secondly, EM imputation based on missing pattern analysis is applied to deal with missing data to obtain the unbiased data set as a benchmark. Thirdly, the null hypothesis that the model parameters estimated with and without imputation are equal is statistically tested using independent-sample T tests and further the internal validity performed in terms of R-squared coefficients is used to identify the discrepancy of model predictions between with and without imputations. Finally, one critical indicator – value of travel time (VOTT) is evaluated considering the effects of missing data. The results confirm that the respondents and non-respondents are quite different in terms of the social-economic background in the developing cities and further show that not only the missing rates but also the missing patterns greatly affect the performance of mode choice model in terms of model parameters and the prediction ability. The calculation of VOTT reveals that the VOTT affected by INR tends to be overestimated.     

呼和浩特至张家口客专本线客流预测研究

随着社会经济的快速发展,我国铁路客运业也得到迅猛发展。铁路客运量的预测是运能分配、产品设计以及制定营销策略的基础。使用我国铁路客流预测普遍采用的“四阶段”预测法对新建呼和浩特市到张家口市本线客流进行预测。在有无呼和浩特至张家口客运专线的情况下,首先,使用重力模型对本线直接客运需求进行预测;其次,使用logit模型对直接需求进行运输方式分配;最后,在有呼和浩特至张家口客运专线的情况下对产生的转移运量和诱增运量分别进行计算。计算结果证明,呼和浩特至张家口客运专线对于本线旅客出行影响较大,结论可为本线旅客列车开行方案制定提供依据。     

Introducing alternative fuel vehicles in Hong Kong: views from the public light bus industry

Hong Kong was the first place in the world to implement a trial scheme to convert all public light buses (PLBs) on the road from diesel to alternative fuel vehicles (AFVs). The scheme, however, did not receive much support from PLB operators. At present, there is a rich literature on households’ demand for AFVs (especially in the USA). However, there have not been many studies about the demand for commercial AFVs in the business and public transport sectors. Since light buses running on alternative fuels are not widely available in the Hong Kong market, a stated preference (SP) survey was conducted to solicit the preferences of PLB operators on eight commercial vehicle attributes and seven forms of government support. The SP data are analyzed by multinomial logit (MNL) models. Detailed analyses on market segmentation and price elasticities follow. The results are of theoretical and practical significance.