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。     

新型城镇化背景下的县域农村公路网规划研究——以济南市济阳县农村公路为例

农村公路网是区域路网的重要组成部分,对于实现新型城镇化具有重要意义。笔者从促进县域产业全面发展的角度出发,以济南市济阳县农村公路为例,对农村公路网的规划方法进行研究。在传统节点重要度法基础上提出了基于镇村体系、特色农业布局和生产出行的重要度布局规划方法。在统筹县域交通发展的基础上,提出公路网体系构建方案,并提出基于量化指标的公路网模糊评价方法     

构建现代综合交通运输体系,塑造区域发展战略格局

交通运输是塑造区域发展格局的重要力量。国家"十三五"现代综合交通运输体系规划提出,要突出对"一带一路"建设、京津冀协同发展、长江经济带发展三大战略和新型城镇化、脱贫攻坚的支撑保障,提高国际通道保障能力和互联互通水平,形成便捷高效、开放融合、安全绿色的现代综合交通运输体系。新时期的交通发展,必须着力发挥三个作用:一是增强引领作用,构建交通促进区域协调发展新机制;二是发挥先导作用,完善以城市群为主体形态的新型城镇化空间格局;三是强化支撑作用,打造国际互联互通网络。     

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。     

Empirical estimation of price and income elasticities of air cargo demand: The case of Hong Kong

This paper estimates the price and income elasticities of air cargo demand and examines how they may change after the 2008 financial crisis. Using a set of time series data, we simultaneously estimate the aggregated demand and supply functions of air cargo at Hong Kong International Airport (HKIA). We find that during the entire sampling period of 2001–2013, the price elasticity for air cargo transport demand at HKIA ranges from −0.74 to −0.29, suggesting that air cargo demand in Hong Kong reacts negatively to price (as expected) but does not appear to be very sensitive to price. The income elasticity ranges from 0.29 to 1.47 and appears sensitive to seasonality adjustment approaches. However, in terms of the speed of changes, air cargo demand changes much faster than overall economy, indicating the presence of a pro-cyclical pattern of air cargo traffic with respect to the overall economy. Our analysis shows that air cargo demand becomes more sensitive to changes in both price and income after 2008.     

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.