基于熵权物元模型的客运站城市交通可达性评价研究

文章以客运站的城市交通可达性作为研究对象,并以兰州西站为例,运用物元分析模型,分别从空间可达性、时间可达性和综合交通环境影响3个大方面选取了经由车站的公共交通线路数、公交车平均等待时间、周边路段饱和度等10个指标,同时利用熵权法计算出各个指标的权重对兰州西站城市交通可达性进行了评价研究。     

基于互联网开源数据的综合客运枢纽规划策略

综合客运枢纽的合理布局对便捷出行、引导城市空间格局优化具有重要意义。本文提出通过网络爬虫技术和互联网地图API抓取实时路况信息建立枢纽时空可达性模型优化客运枢纽布局的方法,以汕头市和高德地图API为例,结合GIS空间分析和可视化技术分析汕头市客运枢纽可达性分异特征及原因,从交通可达性视角结合城市空间发展趋势提出汕头市综合客运枢纽布局方案和发展对策。研究结果表明本文方法融合实时交通信息,可为铁路枢纽地区交通治理提供合理的决策支撑。     

基于空间句法的北京市路网可达性评价

北京市是我国机动车保有量最高的城市之一,伴随着城市建设和经济发展,长期出现了交通流量空间分布不均的问题。文章以北京市四环内的路网为研究范围,基于空间句法的轴线模型理论,采用Google Earth路网数据,运用Depthmap软件绘制路网轴线模型图和计算空间分析变量值,对城市环路的整合度、连接度等相关因素进行道路的可达度和交通流量评价,并将评价结论应用于典型路段地区进行分析,总结出北京城市环路的交通流量时空分布特征。结果表明:整合度高、连接度低的区域,通行顺畅,景观可达性强;整合度低、连接高的区域,交通可达性较强;整合度低、连接度低的区域易形成拥堵;整合度高且连接度高的区域,交通可达性较低。同时根据分析结果提出优化方案,以期促进交通流量空间分布问题早日解决。     

基于空间网络分析的区域交通模式比较:以上海都市圈为例

以上海都市圈区域交通发展模式研究为目标,基于空间网络分析技术分别建立上海都市圈轨道网与道路网的空间句法线段分析模型,并以整合度指标分别定量评价区域内轨道网和道路网各空间组团的可达性。结果表明,都市圈道路网的空间可达性明显优于轨道网,都市圈交通体系缺乏能够与区域发展格局相匹配的轨道网络。结合上海市都市圈发展背景及交通运输方式特征对比,得出结论:构建高密度、多层次的区域轨道交通网络,以轨道交通引导区域空间发展规划是上海都市圈区域交通发展的较优模式。     

浅谈呈贡新区自行车交通复兴

浅谈昆明呈贡新区独有自然气候、地理优势及高铁和地铁投运后自行车交通发展的机遇.通过自行车在交通模式中的使用优势分析表明:①自行车便性、灵活性弥补新区地铁可达性,自行车换乘地铁高效融合其准时、舒适、便捷特性,并有效解决最后1km难题;②改善步行和自行车出行空间加速新区多模式混合型社区发展,并扩大就业和经济活动空间;③新区高校聚集,大学生主力军将成为自行车文化复兴导火索,加速新区交通模式新格局的形成.     

大伦敦职住空间关系及通勤交通研究

超大城市的职住空间关系和庞大的通勤交通需求是构建高效综合交通系统面临的严峻挑战。以大伦敦地区为例,面对中心区人口增速回归和就业密度攀升,职住空间分布圈层化、走廊化的发展趋势,大伦敦构建了多模式、多层次的综合交通体系来应对日益增长的通勤压力,可为我国超大城市提供经验借鉴。     

城际出行链视角下的高铁可达性分析

为探究“门到门”视角下的高铁服务能力,本文从高铁城际出行链视角出发,以成渝间城际出行为例进行实证分析。利用百度地图API获取市内衔接交通出行时间,对同城高铁车站可达性进行评价;综合考虑市内出行和城际出行,选取面积和人口覆盖率指标,建立城际高铁可达性计量模型。结果表明：高铁车站衔接交通行程时间圈层结构显著,受到城市交通网络和出行方向的影响;城际高铁可达性不仅与衔接交通出行模式的相关,还受到发车站选择的影响,可通过优化列车接入站方案来提高整体可达性。     

基于时空可达的城市轨道交通末班车时刻表优化

在城市轨道交通网络化运营中,优化末班车时刻表对于提高网络整体的运营效益具有重要意义。既有研究主要是从旅客换乘需求出发,本文提出了基于时空可达的城市轨道交通末班车时刻表优化方法,从可达性和换乘需求两方面构建双目标的混合整数规划模型,引入了约束系数constraint-α,用Cplex软件求近似最优解,最后以C市地铁为例验证模型的有效性。结果表明本文编制的末班车时刻表可以解决末班车条件下多次换乘的可达问题,在保证较高网络可达性的基础上,增加线网整体的换乘客流量,对于提高城市轨道交通夜间服务水平和网络化运营效益具有重要意义。     

基于出行效用的城市轨道交通时空可达性研究

随着社会的快速发展,满足个性化需求是现代地理服务软件、交通服务部门的目标之一,基于活动出行的时空可达性研究更具实践意义。本文综合时空约束理论与效用模型,提出了基于出行效用的城市轨道时空可达性模型,其影响因子不仅包含了站点的活动吸引力、个体出行的时间和费用成本,还有站点在整个轨道交通系统中的区位因素。和以往模型相比,考虑的影响因素更加全面,实现了更接近于反映真实状况的个人出行可达性研究。最后,通过对广佛地铁可达性进行实证验算,结果表明该方法在分析特定时空约束条件下可达性分布特征的有效性,可为个体出行活动地点推荐以及智能交通出行提供最优的出行选择方案。     

综合交通发展的关键词

在前不久召开的全国综合交通发展座谈会上，优化交通资源配置成为一个主要议题。优化交通资源配置，各个行业都会有不同的理解。对于综合交通系统而言，优化交通资源配置就是要实现交通一体化，使各种交通方式有效衔接、取长补短，以最少的资源占用实现交通高效率、高质量的可达性。     

集聚经济视角下轨道交通投资对城市系统均衡的影响

随着城镇化进程加快,城市规模增加所带来的集聚效应和交通拥堵等负外部性之间的矛盾越来越突出,优化城市交通基础设施建设是缓解该矛盾的重要举措。本文同时考虑了集聚经济和交通拥挤两种外部性,构建并求解了一个两区域城市空间结构模型,分三种情况探究了轨道交通的投资引入和道路容量的优化对城市规模和城市空间结构均衡的影响。结果表明,轨道交通的投资引入能够增加城市人口规模和社会福利,使城市结构更加紧凑。但是,随着集聚经济水平的提高,城市规划者应逐步完善公交配套设施,以降低公交拥挤成本,提高公交出行分担率;还应制定相应的福利政策,避免由于个体效用下降而导致人口流出。     

Evaluating the significance of highway network links under the flood damage: An accessibility approach

This paper conducts an analysis to assess the significance of highway network links in Maryland under flood damage. An accessibility index is derived to incorporate the distance-decay effect and the volume of traffic influence on the transportation network. The accessibility level of individual counties and the state as a whole is checked before and after the hypothetical disruption of individual links within the floodplain. The results indicate that critical links identified based on the distance-only and the distance-traffic volume criteria appear to be different, implying that the priority of retrofit might also vary depending on what criterion to choose. The percentage loss of accessibility due to the disruption of a link is generally greater in the latter. However, distance-only consideration results in a more prominent spatial distribution pattern of links in percentage loss induced. Some links remain significant in both cases. Especially if the disruption of a certain link does not have an alternative solution (for example, if the link is the only way in and out of a certain county) and if counties connected by the link are low accessibility counties, the two criteria may produce a similar outcome.     

Optimal cordon pricing in a non-monocentric city

This paper examines the effect of cordon pricing based on an urban spatial model of a non-monocentric city where trips may occur between any pair of locations in the city. The model describes the spatial distribution of trip demand and traffic congestion under alternative pricing schemes. We evaluate the efficiency of resource allocation by comparing three schemes: no-toll equilibrium, first-best optimum, and optimal cordon pricing. Optimal cordon pricing is defined as a combination of cordon location and toll level that maximizes the social surplus in a city. Simulations show that cordon pricing is not always effective for congestion management: cordon pricing tends to be effective as the urban structure is more monocentric.     

A comparative analysis of transportation-based accessibility to mental health services

The demand for mental health services has been growing stronger over the last couple of decades. This indicates the need to study and assess the access to these mental health services especially with a focus on the vulnerable populations having the greatest need. As such, this paper presents a Geographical Information Systems (GIS)-based analysis in order to study and evaluate the accessibility of mental health facilities using the information on the spatial distributions of population and facilities, and regional traffic characteristics. For this purpose, different age group segments are utilized including the total population as well as those aged between 18 and 21, 22 and 49, 50 and 64, and those aged over 65 and 85. Focusing on the State of Florida, spatially detailed accessibility metrics are calculated with regard to healthcare facilities using travel times between population block groups and these critical mental health facilities. These estimates are used to calculate the weighted county accessibility scores for each county. Findings clearly delineate those counties that lack access to mental facilities, especially those in Northwest Florida, a demographically diverse and substantially rural region. This type of analysis can help planners and policy makers develop better strategies in order to provide adequate mental health care options needed in targeted locations.     

Spatiotemporal evolution of China’s railway network in the 20th century: An accessibility approach

The interrelatedness of transportation development and economic growth has been a constant theme of geographic inquiries, particularly in economic and transportation geography. This paper analyzes the expansion of China’s railway network, the evolution of its spatial accessibility, and the impacts on economic growth and urban systems over a time span of about one century (1906–2000). First, major historical events and policies and their effects on railway development in China are reviewed and grouped into four major eras: preliminary construction, network skeleton, corridor building, and deep intensification. All four eras followed a path of “inland expansion.” Second, spatial distribution of accessibility and its evolution are analyzed. The spatial structure of China’s railway network is characterized by “concentric rings” with its major axis in North China and the most accessible city gradually migrating from Tianjin to Zhengzhou. Finally, the study indicates that railway network expansion has significantly improved economic development and heavily influenced the formation of urban systems in China.     

Measuring post-disaster transportation system performance: the 1995 Kobe earthquake in comparative perspective

Recent earthquake disasters have caused major damage to transportation networks, leading to significant economic disruption. While this suggests the need to evaluate total system performance in transportation risk assessment, in addition to examining the vulnerability of individual components such as bridges, no appropriate measures currently exist. This paper develops post-disaster system performance measures and applies them to the urban rail and highway transportation systems in the Kobe, Japan, region devastated by the 1995 Hyogoken–Nanbu earthquake. Performance is evaluated in terms of network coverage and transport accessibility. Performance degradation was much more severe for highways and railways than for other lifeline infrastructure systems. Both transportation systems fared poorly in the disaster but service restoration proceeded much more rapidly for rail. The restoration of highway system performance correlated closely with the recovery of highway traffic volumes. The paper further develops a measure of subarea transport accessibility and applies this to Kobe’s constituent city wards. Results indicate substantial spatial disparity that is maintained throughout the restoration period. Comparisons with the 1989 Loma Prieta and 1994 Northridge earthquakes in the US show that although these disasters caused notable damage to highway bridges, system performance degradation was small in comparison with the Kobe experience. The paper argues that explicitly measuring transportation system performance can greatly facilitate both understanding the effects of historic disasters and preparing for future hazard events.     

Do new sources of traffic data make the application of Chaos Theory to traffic management a realistic possibility?

Current signal systems for managing road traffic in many urban areas around the world lack a coordinated approach to detecting the spatial and temporal evolution of congestion across control regions within city networks. This severely inhibits these systems’ ability to detect reliably, on a strategic level, the onset of congestion and implement effective preventative action. As traffic is a time-dependent and non-linear system, Chaos Theory is a prime candidate for application to Urban Traffic Control (UTC) to improve congestion and pollution management. Previous applications have been restricted to relatively uncomplicated motorway and inter-urban networks, arguably where the associated problems of congestion and vehicle emissions are less severe, due to a general unavailability of high-resolution temporal and spatial data that preserve the variability in short-term traffic patterns required for Chaos Theory to work to its full potential. This paper argues that this restriction can now be overcome due to the emergence of new sources of high-resolution data and large data storage capabilities. Consequently, this opens up the real possibility for a new generation of UTC systems that are better able to detect the dynamic states of traffic and therefore more effectively prevent the onset of traffic congestion in urban areas worldwide.     

基于LVQ网络的城市交通安全态势评估模型研究

文章基于城市交通安全态势评估的重要性,提出了一个比较完善的城市道路网交通安全态势评估系统总体框架,构建了基于LVQ网络的宏观城市交通安全态势评估模型,并采用Matlab7.0语言对该模型进行了仿真分析。仿真结果表明该模型能够对城市宏观交通的安全态势进行评价。     

Assessing the impact of tactical airport surface operations on airline schedule block time setting

With the growth of air traffic, airport surfaces are congested and air traffic operations are disrupted by the formation of bottlenecks on the surface. Hence, improving the efficiency and predictability of airport surface operations is not only a key goal of NASA’s initiatives in Integrated Arrival/Departure/Surface (IADS) operations, but also has been recognized as a critical aspect of the FAA NextGEN implementation plan. While a number of tactical initiatives have been shown to be effective in improving airport surface operations from a service provider’s perspective, their impacts on airlines’ scheduled block time (SBT) setting, which has been found to have direct impact on airlines’ on-time performance and operating cost, have received little attention. In this paper, we assess this impact using an econometric model of airline SBT combined with a before/after analysis of the implementation of surface congestion management (SCM) at John F. Kennedy International Airport (JFK) in 2010. Since airlines do not consider gate delay in setting SBT, we find that reduction in taxi-out time variability resulting from SCM leads to more predictable taxi-out times and thus decreases in SBT. The JFK SCM implementation is used as a case study to validate model prediction performance. The observed SBT decrease between 2009 and 2011 at JFK is 4.8 min and our model predicts a 4.2 min decrease. In addition, Charlotte Douglas International Airport (CLT) is used as an example to demonstrate how different surface operations improvements scenarios can be evaluated in terms of SBT reduction.     

Mapping spatial accessibility of public transportation network in an urban area – A case study of Shanghai Hongqiao Transportation Hub

Accessibility is a key metric when assessing the efficiency of an urban public transportation network. This research develops a methodology for evaluating spatial accessibility of a system with multiple transportation modes in an urban area, Shanghai Hongqiao Transportation Hub (SHTH) and its surrounding area. The method measured total traveling time as an accessibility indicator, which summed the time people spent on walking, waiting, transfer and transportation in a journey from the SHTH to destinations. Spatial accessibility was classified into five levels from very high to very low. The evaluation was conducted at a cell-by-cell basis under an overall scenario and three specific scenarios. Evaluation results were presented in a series of maps. The overall accessibility scenario shows a concentric-ring trend decreasing from the SHTH to the fringe of the study area. Areas along the metro lines generally have a much higher accessibility than those along the bus lines with some exceptions where bus routes play a more important role. Metro stations identified as either time-saving or time-consuming points are mainly distributed around the urban center. Some suggestions are proposed for improving accessibility of public transportation network in the study area. The results from this study provide a scientific basis and useful information for supporting decision-making on urban planning, and assisting dwellers to travel in a time-efficient manner. The methodology offers a simple, flexible way to the spatial evaluation, metro station identification and network modification of accessibility of public transportation systems with multiple transportation modes.