考虑风险规避和认知更新的日常择路行为演进

为了刻画出行者的日常择路行为,利用动力学系统方法和不动点理论,建立了一个集成风险规避和认知更新的演化模型,分析了演化过程的稳定性,并在一个简单网络上进行了验证。发现在模拟开始的前15 d内,出行时间预算、路径期望出行时间、实际出行时间以及路径流量都出现了较大的波动,但经过大约30 d的摸索以后,开始趋向于随机用户均衡状态。分析结果表明:模型所设计的择路演化过程类似于经典的相继平均算法的计算过程,可以确保收敛到稳定状态,并与初始状态参数的取值无关。     

驾驶员道路认知特性模型

为了提供驾驶员车速控制模式建模所需的试验数据依据和评语隶属函数,采用模糊集合原理和模糊统计试验分析方法,研究了车辆驾驶员对道路结构和交通环境因素的安全性认知与评价思维过程。在实测226处国道二级公路典型路段道路结构数据基础上,根据对131处路段样本评价试验后得到的1 785组有效“专家”认知评语数据,得出了基于0.2-截集的各认知评语非零集和基于0.8-截集的各认知评语确定集,建立了车辆驾驶员对国道二级公路道路结构和交通环境要素的安全性模糊评价评语模糊子集和模拟计算模型。     

山区公路路侧安全定量化评价

路侧安全评价对提高路侧安全、减少道路交通事故具有重要意义。为实现路侧安全定量化评价,本文分析了影响路侧安全的三个不同层次影响因素：车辆驶出路外的可能性、暴露路侧危险环境的频率以及危险严重程度,在此基础上建立了路侧危险指数用于评价路侧安全。最后将该方法用于实际工程路侧安全评价,计算结果表明该方法合理有效,同时通过Kappa统计量验证表明不同评价者运用该方法的安全评价结果一致性较好。     

广西酒后驾驶干预项目调查结果分析

广西酒后驾驶干预项目是在广西南宁和柳州市开展的、针对酒后驾驶的专项干预项目,湖南长沙市为对照城市。文中介绍了干预前后在3市开展的酒后驾驶路边调查结果。32 101名司机接受了呼气酒精含量检测,32 097人接受了问卷调查。经过1 a的公众宣传和强化执法干预活动后,干预城市饮酒驾驶率明显降低,从6.8%降到了1.6%,酒后驾驶法定阈值知晓率明显上升,从14.7%上升到29.2%,被拦截检查过酒后驾驶的司机比例从21.5%上升到32.5%,而对照城市长沙的饮酒驾驶率从3.1%上升至4.4%,说明南宁、柳州两市干预活动取得了显著的效果。     

Port Decision Maker Perceptions on the Effectiveness of Climate Adaptation Actions

Effective adaptation to climate change impacts is rapidly becoming an important research topic. Hitherto, the perceptions and attitudes of stakeholders on climate adaptation actions are under researched, partly due to the emphasis on physical and engineering aspects during the adaptation planning process. Building on such considerations, the paper explores the perceptions of port decision makers on the effectiveness of climate adaptation actions. The findings suggest that while port decision makers are aware of potential climate change impacts and feel that more adaptation actions should be undertaken, they are skeptical about their effectiveness and value. This is complemented by a regional analysis on the results, suggesting that more tailor-made adaptation measures suited to local circumstances should be developed. The study illustrates the complexity of climate adaptation planning and of involving port decision makers under the current planning paradigm.     

Who uses smart card? Understanding public transport payment preference in developing contexts,a case study of Manila's LRT-1

The culture of “tingi-tingi” or sachet economy provides a strong backdrop to better understand the payment mode preference of the riding public in the Philippines. First, the use of single journey tickets (SJT) reflects the purchasing practices amongst the urban poor thereby affecting the promotion and uptake of public transport smart cards. Second, as a glocalization strategy, it can inform what, how, when, and why services that has global uptake can be tailored towards the realities of a differentiated, local market conditions.Categorical principal component analysis (CATPCA) is presented to determine the key variables explaining the likelihood of uptake of smart cards for public transport passengers in the Philippines. The Metro Manila Light Rail Transit Line 1 (LRT-1) presents an appropriate context to examine how the glocalization of smart cards can help improve the quality of public transport services, and to provide planning and policy recommendations on smart card uptake and integrated ticketing, with the end goal of improving public transport provision and management. LRT-1 alongside its change in management, also introduced a new smart card payment system. However, more than half continue to use single journey tickets.The model parameters are estimated using primary survey data collected from LRT-1 passengers. Transit smart card has been widely used around the world and effectively reduces waiting time for passengers who used to purchase paper tickets.The main results of the model reveal that: (1) only groups with high education background, stable income, or with stable job would likely to use smart card; (2) passengers with lower education level, lower income, or with unstable job prefer to use single journey ticket; and (3) the sachet economy is strongly associated with the purchasing practices amongst Filipinos, particularly the urban poor, hence may affect the promotion and uptake of public transit smart cards. These findings may inform changes to the introduction of alternative payment schemes and the planning of public transport policies that recognise the need for an effective glocalization strategy, paving the way towards improved public transport service and provision.     

基于非接触远程智能感知的桥梁形态监测试验

为进一步提高利用非接触式影像监测大型桥梁安全状态的精度与效率,实现结构健康监测系统兼有经济、可信且全息的技术理论优势,提出依据结构全息影像序列数据的非接触式机器视觉远程智能感知进行桥梁结构全息几何形态监测的方法。通过单机自动巡转桥梁立面动静影像全息监测系统试验装置获取试验桥在各损伤/作用工况下的原始动静影像数据,根据序列数据在时间、空间上具有强关联信息的特性,分别构建降噪及抗扰动单元、欧拉运动放大单元及运动信息提取单元进行全息几何形态测量,以历次试验监测数据为样本数据集,利用分层思想依次建立数据抽样和结构几何信息间映射的数学网络模型,经结构设计不断训练、调试与优化桥梁力学行为智能感知网络,最后获取试验桥在试验过程中的全息变形、全息变形包络谱、全息位移时程曲线。研究结果表明：该方法获得的数据与传统的常规接触式传感器实测值基本吻合,试验桥在各工况下的曲线变化趋势基本一致,全息变形测量值平均误差12.21%,全息变形包络谱测量值平均误差9.06%,全息位移时程曲线测量值平均误差8.55%,对环境规律噪声信号筛除效率为81.9%,基于非接触远程智能感知的桥梁形态监测真实、连续、敏感、较为准确地反映了结构在各损伤/作用工况下的真实形态变化,可为后续进一步研究结构状态演绎以及损伤智能化识别方法奠定基础。     

基于立体感知技术的海上风场水域交通安全监管系统

对我国海上风场水域的交通安全监管现状进行分析,提出基于立体感知技术的海上风场水域交通安全监管系统方案。对该系统的组成和架构进行设计,并在福清兴化湾风电场一期项目中对其监管效果进行测试验证。结果表明,该系统能实现较好的监管效果,该系统的提出有助于提升海上风场的安全防御能力和交通安全管理能力,为我国海上风场的建设和安全监管提供理论参考。     

Assessing urban sidewalk networks based on three constructs: a synthesis of pedestrian level of service literature

ABSTRACT

Pedestrian Level of Service (PLOS) models are widely used to assess walking facilities. These models have been in existence since the 1970s, wherein the process broadly consists of three steps, i.e. attribute selection, model calibration, and classification of model results into service-level categories, based on Measures of Effectiveness (MOEs). This paper reviews existing sidewalk PLOS studies based on their association with the three constructs of flow characteristics, built environment and users’ perception, which in combination represents the entire walking environment spectrum, as has been indicated by existing researchers. Forty-seven PLOS studies, along with eight review papers, written by authors from the Americas, Europe, Asia and Australia, between the years of 1971 and 2019, are analysed in this review. The review finds that although 49% of the studies employed both qualitative and quantitative data for their respective methodologies, but none of them use all the three broad constructs in a combined fashion. Also, in selecting the attributes to be used for developing the PLOS, these studies have only referred to previous literature available at that point in time, and not employed any consistent and robust method in selecting context-specific attributes. When it came to the preferred analysis technique, 60% of the studies favoured the use of the regression technique while calibrating their model, whereas 22% used a points-based marking scheme. Finally, 89% of the studies manually classifies the PLOS model results to respective service levels (i.e. letter grades), as opposed to utilising a classification algorithm. In addition, this review could identify only one paper that describes a PLOS based on pedestrian route directness, which is a measure of pedestrian network connectivity. In view of these findings, the review paper suggests the need of a robust methodology in selection of attributes and the use of innovative modelling techniques, both of which could allow the utilisation of all three constructs. Also, such advanced modelling techniques could bypass the need for categorising service levels manually. Finally, the study advocates the use of network connectivity measures in developing sidewalk PLOS, as it is an important part of the built environment.     

Quantifying traveler information provision in dynamic heterogeneous traffic networks

Information is effectively the same as a change in uncertainty perceived by an observer. This paper adopts the strict definition of information from Shannon’s Information Theory and provides procedures for quantifying effective provision of traveler information, considering it to be equivalent to the change of perceived uncertainty. The proposed method combines a cognitive grouping theory and an information learning scheme at an individual’s level to evaluate the dynamic information provision in the unit of a bit. Such numerical quantification can be meaningful in evaluating alternatives with more fine-grained information provision strategies and understanding their equity impact. Quantifying information in a manner consistent with Information Theory also provides a ‘shared language’ that facilitates more constructive discussion among stakeholders from different backgrounds. The case study is conducted on a heterogeneous dynamic traffic network near Downtown Los Angeles for evaluating different alternatives of a proposed dynamic message board in terms of its location and dynamic content.