城市轨道交通与可持续发展

面对城市化进程加快带来的交通需求迅速增长和城市布局的重新调整,探讨了城市轨道交通与可持续发展的关系。首先介绍了城市交通可持续发展的3E原则。以上海市为例,通过常年的调查研究,从轨道交通网络规模效应、轨道交通与城市空间结构、轨道交通与社会公正性3个方面进行了分析。最后,总结了轨道交通促进可持续发展的基本策略,并提出了我国城市交通发展与土地开发建设的5D原则,即POD〉BOD〉TOD〉XOD〉COD。     

效率与公平视角下的应急公交接驳调度优化

城市地铁突发故障后,需要采用高效的应急公交接驳方法疏散滞留乘客,减小社会和经济损失.建立两阶段优化模型,对每辆车从存车点出发后依次前往各站运输乘客的接驳过程进行决策.阶段 1,从管理部门角度最小化疏散时间;阶段 2,在此基础上,从乘客角度降低乘客延误,优化目标分别考虑了效率与公平原则.由于现有优化软件求解阶段 2效率过低,构造了针对性的禁忌搜索(TS)算法提高求解速度.最终通过算例验证了算法和模型的可行性,对比了效率与公平原则下的疏散效果,展示了两者的权衡关系：效率原则可能导致乘客服务水平不均;而公平原则提供了更均衡的疏散服务,但系统延误相对更高.     

通过停车收费筹措公共服务资金

很多城市的低收入社区面临两大突出难题：超负荷的路内停车和低配置的公共服务。通过构建一项政策可以同时解决这两个难题：基于市场价格征收路内停车费,并将其收入用于本地公共服务运营。基于北京一处胡同改善项目发现,通过合理收取停车费,该社区用于卫生、治安、景观和停车管理的投资能够在不到三年内回收。同时,该项目社区中只有35%的住户拥有私人小汽车,拥车住户的家庭年收入是无车住户的近3倍。     

Dockless bike-sharing systems: what are the implications?

ABSTRACT

The emergence of dockless bike-sharing services has revolutionised bike-sharing markets in recent years, and the dramatic growth of shared bike fleets in China, as well as their rapid expansion throughout the world, exceeds prior expectations. An understanding of the impacts of these new dockless bike-sharing systems is of vital importance for system operations, transportation and urban planning research. This paper provides a first overview of the emerging literature on implications of dockless bike-sharing systems for users' travel behaviour, user experience, and relevant social impacts of dockless bike-sharing systems. Our review suggests that the dockless design of bike-sharing systems significantly improves users' experiences at the end of their bike trips. Individuals can instantly switch to a dockless shared bike without the responsibility of returning it back to a designated dock. Additionally, the high flexibility and efficiency of dockless bike-sharing often makes the bike-sharing systems' integration with public transit even tighter than that of traditional public bikes, providing an efficient option for first/last-mile trips. The GPS tracking device embedded in each dockless shared bike enables the unprecedented collection of large-scale riding trajectory data, which allow scholars to analyse people's travel behaviour in new ways. Although many studies have investigated travel satisfaction amongst cyclists, there is a lack of knowledge of the satisfaction with bikeshare trips, including both station-based and dockless bikeshare systems. The availability and usage rates of dockless bike-sharing systems implies that they may seriously impact on individuals' subjective well-being by influencing their satisfaction with their travel experiences, health and social participation, which requires further exploration. The impact of dockless bike-sharing on users' access to services and social activities and the related decreases in social exclusion are also relevant issues about which knowledge is lacking. With the increases in popularity of dockless shared bikes in some cities, issues related to the equity and access and the implications for social exclusion and inequality are also raised.     

Does green transportation promote accessibility for equity in medium-size U.S. cites?

The link between accessibility and social equity attracts much attention for promoting sustainability. However, there is no comprehensive approach to elevate the role of accessibility in evaluating transportation system over social equity by considering the variety of urban opportunities and population groups from green transportation perspective. Our goal is to develop such a framework to evaluate transportation equity by focusing on accessibility via transit and cycling. Applying the framework to Fresno, California, and Cincinnati, Ohio with different development patterns, we delineate service areas at block-group level with five time-thresholds. The service area is used to count the number of urban opportunities: jobs, dining, churches, libraries, parks, multi-use paths, schools. We then use statistical comparison and geographical mapping to identify accessibility gap to these opportunities between advantaged and disadvantaged groups defined by income, property value, education, vehicle ownership, race, and age. The results indicate the extent of differences in accessibility is sensitive to threshold specification of grouping population. The findings suggest that the efficiency of transit service needs to be improved to reach the same level of cycling, while they do help with the accessibility for economically disadvantaged neighborhoods. Considering school enrollment, the accessibility to opportunities in Fresno performs differently while students in Cincinnati benefit from good accessibility to most resources. The results of accessibility to multi-use paths highlight the need of providing more efficient green transportation facilities for less wealthy neighborhoods. Variation in accessibility between groups underscores the importance of developing policies to meet the needs of diverse social groups.     

Transport and equity in Latin America: a critical review of socially oriented accessibility assessments*

ABSTRACT

A growing concern for mobility-related social inclusion and equity is evident from both academic research and planning best practices. Scholarly research promotes accessibility as the main aim of transport planning, assuming it as the evaluative approach that better conveys how mobility contributes to individuals' well-being and participation in social life. Accessibility can be crucial to address the socio-spatial inequalities that characterise manifold settings across the world. Amongst them, Latin American countries have been keen in tackling such imbalances through mobility-related interventions, as the renowned cases of Curitiba, Medellin and Bogotá show. The widespread interest in mobility as both a cause and effect of social disparities has generated an increasing stream of work that examines Latin American settings through the lenses of accessibility. This paper aims at critically reviewing the growing scholarly works that, providing accessibility-based evaluations, has examined issues of transport and equity in Latin America. Proposing a novel conceptual framework that considers the underlying ethical stance, components of accessibility and implications for planning and policy, this work examines what approaches, features and indicators are present in the current literature, as well as what settings have been taken into consideration by scholarly research. Moreover, the review has an explicit operational interest, to define what indicators are relevant or missing to assess accessibility in the light of social concerns, as well as to consider the current and potential implications that such research findings have on transport planning and policy. The review highlights how a growing but still limited body of work has examined transport and equity in Latin America, suggesting academic, technical and operational avenues to enhance theoretical and practical approaches to the issue.     

���ڹ�ƽ�����ȿ��ǵ������������

网络设计问题通常以最小化系统的总出行费用作为优化的唯一目标,所求得的最优解往往不能满足交通工程的实际要求。本文分析了在道路交通规划的工程实践中普遍存在的公平性和优先性问题,以网络设计问题的经典数学模型为基础建立了考虑公平和优先的网络设计问题数学模型,针对模型的特征设计了求解模型的遗传算法。最后,以一个实验道路网的分析为例,说明了数学模型和遗传算法的具体应用。该实例表明,论文所提出的模型和计算方法是非常有效的,能够为交通规划提供非常丰富的信息,协助决策者做出科学明智的选择。     

One manufacturer's approach to improving jet transport fuel efficiency

In the face of rapidly escalating costs of aircraft fuel, since the early 1970s, the aerospace industry has embarked on a program of measures to reduce fuel consumption. This article describes an integrated set of measures which have been undertaken by Lockheed‐California to improve the fuel requirements of the Tristar, a wide‐bodied three engine medium to long range aircraft. Measures include operational changes, improvements to maintenance practices, long term hardware modifications and technological advances.     

2020至2025赣州新能源汽车发展面临的问题及建议

中国是世界能源消费大国之一,节能减排是当前经济社会发展进程中必须面临的挑战。同时中国要从汽车大国迈向汽车强国,发展新能源汽车产业是不可逆的。本文通过分析补贴退坡及外资股比放开对国内新能源汽车发展带来的影响,阐述了赣州新能源汽车产业发展面临的问题,并从人才端,基础设施端等方面着手,为赣州新能源汽车产业的发展提出建议。     

快速城市化地区公共交通的空间剥夺特征研究

为合理评估快速城市化地区公共交通系统的公平性,改善公共交通系统的空 间剥夺问题.在构建公共交通空间剥夺评价指标体系的基础上,运用SPSS 对指标体系进 行因子分析;基于空间分析方法获取公共交通的空间剥夺特征,并以昆明市呈贡新区为 例进行验证;最后基于区域剥夺补偿原理,提出了公共交通资源的均衡配置策略.结果表 明,呈贡新区的公共交通空间剥夺总体呈现“多核心+局部放射”的空间形态,公共交通的 空间剥夺因子主要包括公共交通服务因子和公交线网覆盖率因子,建立的公共交通空间 剥夺综合指数模型能够获取各交通小区的公共交通空间剥夺分异特征.