A bi-objective cyclist route choice model

It is widely acknowledged that cyclists choose their route differently to drivers of private vehicles. The route choice decision of commuter drivers is often modelled with one objective, to reduce their generalised travel cost, which is a monetary value representing the combined travel time and vehicle operating cost. Commuter cyclists, on the other hand, usually have multiple incommensurable objectives when choosing their route: the travel time and the suitability of a route. By suitability we mean non-subjective factors that characterise the suitability of a route for cycling, including safety, traffic volumes, traffic speeds, presence of bicycle lanes, whether the terrain is flat or hilly, etc. While these incommensurable objectives are difficult to be combined into a single objective, it is also important to take into account that each individual cyclist may prioritise differently between travel time and suitability when they choose a route.This paper proposes a novel model to determine the route choice set of commuter cyclists by formulating a bi-objective routing problem. The two objectives considered are travel time and suitability of a route for cycling. Rather than determining a single route for a cyclist, we determine a choice set of optimal alternative routes (efficient routes) from which a cyclist may select one according to their personal preference depending on their perception of travel time versus other route choice criteria considered in the suitability index. This method is then implemented in a case study in Auckland, New Zealand.The study provides a starting point for the trip assignment of cyclists, and with further research, the bi-objective routing model developed can be applied to create a complete travel demand forecast model for cycle trips. We also suggest the application of the developed methodology as an algorithm in an interactive route finder to suggest efficient route choices at different levels of suitability to cyclists and potential cyclists.     

Port choice in container market: a literature review

As a result of the intense changes occurring in port environment over the last decades, new models of competitiveness have been developed, where port authorities try to increase their attractiveness. In this context, one of the most debated issues in this area of research is still the role played by port authorities in defining port competitiveness. The aim of this paper is to provide a review of port choice literature enabling to identify the main port choice’s criteria in order to define the role played by Port Authorities and to point out future lines of research that should be undertaken to fully incorporate current ports’ environment and performance. The results show that although some studies point out the importance of geographical factors in port choice, a larger number of studies defend the increasing role played by port authorities in determining the competitiveness through investing in port infrastructure, improving port efficiency or hinterland accessibility. Despite the existing models contributing on this topic, there are still some gaps in terms of measuring the port performance, including port strategies and studying the port choice for specific industries.     

Network impacts of a road capacity reduction: Empirical analysis and model predictions

In spite of their widespread use in policy design and evaluation, relatively little evidence has been reported on how well traffic equilibrium models predict real network impacts. Here we present what we believe to be the first paper that together analyses the explicit impacts on observed route choice of an actual network intervention and compares this with the before-and-after predictions of a network equilibrium model. The analysis is based on the findings of an empirical study of the travel time and route choice impacts of a road capacity reduction. Time-stamped, partial licence plates were recorded across a series of locations, over a period of days both with and without the capacity reduction, and the data were ‘matched’ between locations using special-purpose statistical methods. Hypothesis tests were used to identify statistically significant changes in travel times and route choice, between the periods of days with and without the capacity reduction. A traffic network equilibrium model was then independently applied to the same scenarios, and its predictions compared with the empirical findings. From a comparison of route choice patterns, a particularly influential spatial effect was revealed of the parameter specifying the relative values of distance and travel time assumed in the generalised cost equations. When this parameter was ‘fitted’ to the data without the capacity reduction, the network model broadly predicted the route choice impacts of the capacity reduction, but with other values it was seen to perform poorly. The paper concludes by discussing the wider practical and research implications of the study’s findings.     

论我国西部开发中经济增长点选择的基本原则

西部开发是全国发展的一个大战略,大思路。作为新世纪的宏伟战略,其重要性既体现在经济上,又体现在政治上。要充分发挥西部开发战略的作用,促进广大西部地区的发展,实现区域经济发展的协调和平衡,选择正确的经济增长点就显得尤为重要。要选择正确的经济增长点,除了要充分了解西部地区目前面临的发展环境和背景之外,还要有正确的思路,坚持正确的原则。西部开发中经济增长点选择应该坚持整体性原则、利益协调原则、发展原则、市场取向原则、后发优势原则及可持续发展原则。     

基于随机效用模型的大城市与卫星城市间交通模式配置研究

在对大城市和卫星城市间复合交通模式进行分析的基础上,结合个人出行特性,提出了大城市和卫星城市间的典型交通模式;基于对个体出行行为的分析,探讨了随机效用理论在交通模式选择决策行为中的应用;以M NL模型为基础,研究了主卫城间复合交通模式的效用因子及标定方法,提出了模型在城间交通模式配置时的应用步骤;结合具体示例进行了分析验证.     

辽宁省滨海公路辽河特大桥桥位及路线方案的选择

本文通过考虑辽宁滨海公路主要控制因素,详细调查相关路网结构,对辽河特大桥桥位和路线方案进行全方位、多角度分析和论证,最终确定推荐方案,其方法对类似工程具有借鉴作用。     

公交线网优化的算法研究

为缩短居民乘车出行时间以及减少公交运营投入,在公交线网优化过程中通常采用具有全局最优的遗传算法。针对基本遗传算法自身的一些缺点,提出了一种改进的遗传算法。该算法在公共交通路线优选过程中运用减少搜索空间、加入最佳保留策略和修正策略的方法,对基本遗传算法中的选择、交叉、变异算子及中止条件进行改进。改进遗传算法能够在保证种群多样性的同时加快收敛速度,较好地避免了基本遗传算法前期容易早熟和后期进化缓慢等现象。实例仿真计算表明,该算法具有比基本遗传算法更高的效率,是优化公交线网的一个有效途径。     

基于前景理论的实时信息下路径选择模型研究

首先介绍了研究路径选择问题的传统理论——“期望效用理论”的不足,对“前景理论”进行了简单概述。在“前景理论”的基本框架下,研究实时交通信息影响下的路径选择问题,分析了出行者的路径选择决策过程。通过选择参照点,建立了价值函数。利用贝叶斯理论,对预测的路径行程时间进行更新与调整。得到决策权重函数之后,建立了路径选择的动态模型。     

考虑汽车共享服务的出行方式选择影响因素研究

为了分析汽车共享服务对城市出行者出行方式选择行为的影响,基于随机效用理论,运用行为调查和意向调查数据,以汽车共享服务、出租车、地铁三种出行方式作为选择肢,构建多项Logit模型,并应用SPSS软件对模型进行拟合检验与参数估计。研究表明：性别、年龄、最常使用交通工具、日常通勤单程距离、出行距离和汽车共享服务收费标准均会对出行者的汽车共享服务选择行为产生显著影响;中青年男性更倾向于选择汽车共享服务出行,且随着出行距离的增加、汽车共享服务收费标准的降低,汽车共享服务被选择的概率会增大;相较于出租车,日常通勤单程距离为20~30km的出行者更倾向于选择汽车共享服务;相较于地铁,最常使用交通工具为私家车的出行者选择汽车共享服务的概率更大。因此,为提高汽车共享服务被选择概率,应提高用户体验、服务水平,合理设置收费标准。     

不同信息下的逐日路径选择行为实验与模型

为研究先进出行者信息系统(ATIS)对出行者逐日路径选择行为的影响,本文基于 Braess路网设计5组具有不同ATIS市场占有率(0、25%、50%、75%、100%)的行为实验.结果表明：3条路径的流量及新增路径保持选择的次数持续波动,随着ATIS市场占有率增大,路网平均行程时间趋于用户均衡,新增路径保持选择的次数呈现增长趋势,且被试对新增路径的选择性偏好增强,Braess悖论的效果也更明显.基于5组实验数据,分别建立普通Logit模型和基于面板数据的随机效应Logit模型刻画路径选择行为.结果表明：当ATIS市场占有率为0时,最佳模型为普通Logit模型;当ATIS市场占有率增大甚至达到100%时,最佳模型均为随机效应Logit模型;未配备ATIS的出行者的个体差异性比配备ATIS的小.