秦皇岛市利用既有铁路发展城市轨道交通的规划方案研究

随着秦皇岛市城市发展和城市结构调整,城区内部铁路的运量正逐年下降,部分铁路货运专用线即将废弃。而秦皇岛市作为著名的滨海旅游城市,近年来旅游人口快速增长,再加上不断增加的本地居民出行需求,其交通拥堵现象越来越严重。参照其他城市利用既有铁路资源发展轨道交通的经验,结合秦皇岛市铁路现状及客流需求分析,提出了利用既有铁路发展城市轨道交通的方案,以缓解交通拥堵,提升城市交通品质。     

Comparison of updating techniques in transferability analysis of work trip mode choice models in developing countries

This study analyzes the performances of updating techniques in transferability of mode choice models in developing countries. A model specification, estimated in Ho Chi Minh City, was transferred to Phnom Penh. Naïve transfer and four updating methods associated with small sized samples were used in the transfer process and were evaluated based on statistical perspective and predictive ability. The study also illustrates the problems faced in model transferability development, due to the lack of available and suitable data in Phnom Penh. This lack is strongly related to different methods and structures applied in collecting the data. Simplified approaches to the difficulties are proposed in the study. The results show that updating ASCs, updating both ASCs and scale parameter, and use of combined transfer estimators all produce significant improvement, both statistically and in predictability, in updating the model. The last two methods have proven to be superior to the first method, owing to the inclusion of transfer bias considerations in the estimations. However, small data samples should not have large transfer bias when using combined transfer estimators. It is also concluded that naïvely transferring a model is not recommended, and Bayesian updating should be avoided when transfer bias exists. Copyright © 2010 John Wiley & Sons, Ltd.     

城市道路立交方案设计

从交通量、周边路网分析、用地性质、交通疏解等影响因素出发,理论上论述了城市道路立交的方案选择,同时结合长沙市湘府路湘江大桥工程两岸接线立交的工程实际案例来论述城市道路立体交叉的设计与优化。     

湖北省城市竞争力比较及其分析

采用AHP层次分析法,利用Excel对反映湖北省12个主要城市的城市竞争力的19项指标进行数据处理与分析,得出其竞争力的综合分值及排名,并对湖北省各地区城市作综合评价。     

CO2 emissions in relation to street-network configuration and city size

The street-network efficiency of tens of British cities in relation to transport fuel consumption and CO₂ emissions are analyzed. The results show a strong linear positive correlation between length entropy and average street length, and a negative correlation between entropy and street density. Also, the results suggest that in a large city the street network is used more efficiently than in a small city, as indicated by the sublinear relations between city size (population) and the number of streets, total length of streets, and the area covered by the street network. The sublinear relation means that these parameters grow more slowly than the city size. By contrast, because a larger fraction of the street network is used at close to full capacity during considerable part of the time in a large city than a small one, the fuel consumption and the CO₂ emissions show a linear relation with city size and superlinear relation with total street length. The superlinear relation means that the CO₂ emissions increase faster than the total street length, a measure of the network size. Thus, large cities may be less energy efficient and environmentally friendly than small cities. In every city the street network needs to interconnect all the buildings, which requires a certain minimum size. In a small city, however, the network is used to a low capacity most of the time so that its relations to fuel consumption and the CO₂ emissions are more favorable than those in a large city.     

Spatial Transferability and Updating Analysis of Mode Choice Models in Developing Countries

ABSTRACT

This article examines the spatial transferability of mode choice models in developing countries. An evaluation of the updating procedure and sample size are also included in the study. Because of the insufficiency of model coefficients in explaining differences in unmeasured modal attributes, naïvely transferring a model is not recommended. An understanding of the transport characteristics in both the estimation context and the application context is required, in order to justify whether a variable is transferable or not. Four updating procedures – updating alternative specific constants (ASCs), updating ASCs and scale parameter, the combined transfer estimator and Bayesian updating associated with three sets of small sample sizes – are applied to improve transferability. In general, the first three approaches produce significant improvements. It is also proposed that a minimum small sample size of 400 observations is necessary for updating purposes.     

大型市政工程施工期间的交通组织与管理——以乌鲁木齐市“田”字形道路建设为例

大型市政工程施工期间,改变了城市道路原有的交通和行车环境,易导致交通拥堵、通行能力下降、安全事故等发生,项目建设前应进行施工期间的交通组织研究分析并优选方案,才能有效地保障施工期间城市交通的良性运转。结合实际案例,着重探讨交通组织及管理措施,可为此类工程建设提供参考。     

桂林交通现状·意识形态·公交优先

该文通过对桂林交通现状的描述,表明现在城市交通拥堵已日趋严重,要想很好地解决城市交通拥堵问题,目前已是关键时期。解决城市交通问题应建立科学的意识形态,只有在科学意识指引下才能做出科学的决策。公交优先已成为老生常谈,而如何将这一思想变成政策并付诸实践,这才是解决问题的关键。接着,根据历年的工作体会并结合大量城市交通现状调查的成果,提出若干条保证公交优先的基本措施,可供决策层在解决城市交通拥堵问题时作参考。     

道路线形安全评估的模糊评价方法探析

通过对道路线形提出了一些评价指标,选取了一条典型道路—淮安市黄河路进行线形的安全性评价。在分析了道路线形的各要素对交通安全影响的基础上,建立了一套评判道路线形安全性的综合评价体系,并利用模糊综合评价的方法建立评价模型,对黄河路段的线形安全性做出评价。最后根据评价的结果,发现黄河路段存在的线形问题,并对其进行改进和优化设计。     

城市地下空间开发与地下交通系统——重庆市解放碑CBD地下交通系统

城市地下交通系统构建是解决现今城市问题的重要措施之一。该文针对这一课题,探讨了城市地下交通系统的组成及其对改善城市空间的重要作用。结合重庆市解放碑CBD交通现状评价分析与城市发展规划定位等因素,提出解放碑CBD地下交通系统方案——地下车行道路网络、地下快速人行系统。该方案对改善解放碑CBD现状交通和城市环境、提升该区域的经济活力具有重要意义,可作为其它城市发展城市核心区地下道路系统的参考和借鉴。