城市道路建设中的交通组织与安全保障技术探讨

文章立足于城市道路建设的交通组织基本原理,首先从施工道路现状调查获取有关数据、针对占道路施工进行设计、施工交通组织方案设计来分析城市道路建设方案设计;接着阐述了城市交通建设交通组织方案的实施;最后还从制度、资金、技术等方面详细探讨城市道路建设中的交通组织与安全保障.     

城市道路改扩建工程的管理及控制要点

城市道路改扩建工程是减缓交通压力,改善城市道路情况和城市环境的重要的系统的工程。研究主要结合城市道路改扩建工程实践以及自身施工经验,着重从城市道路改扩建工程的管理工作和施工控制要点两个方面详细分析了如何做好城市道路改扩建工程,给同行提供参考。     

我国城市道路交通安全问题及对策

伴随着城市人口、机动车保有量以及出行距离的不断增加,城市交通出行总量迅速攀升,对城市交通安全、畅通、生活环境提出了更大的挑战和更高的要求。首先从城市交通复杂性、城市交通供需矛盾和城市交通问题频发三个方面分析了我国城市道路交通的特点。然后以城市交通安全为切入点,从城市交通事故、城市交通违法和事故成因分析了我国城市道路交通安全存在的问题。最后,从道路及设施、交通宣传、交通执法、绿色交通出行和交通环境五个层面提出相应的对策建议。     

城市道路设计交通分析及预测

交通量预测好坏直接关系到城市道路的使用和安全。结合城市道路设计实体工程,详细阐述了城市道路的限制交通调查与分析和交通量预测,为城市道路交通预测问题提供了思路和借鉴。     

直流通行城市道路设计

伴随着城市的快速发展,城市道路交通问题正在成为制约社会经济进一步发展的不良因素。在分析当前城市道路设计中存在问题的基础上,探讨了"直流通行"城市道路设计方案的内容及其具有的优势。     

城市道路交通设计思路及技术关键要点研究

为了满足城市居民的出行需求,提高城市道路交通设计水平,分析城市道路交通设计的特点和基本要求,提出城市道路交通设计思路和技术关键要点,以期为同类型设计工作提供参考。     

城市桥梁声屏障设计及交通噪声控制研究

城市桥梁交通噪声污染随着城市道路的发展和车辆增多日益严重,引起了人们的普遍关注。文章以北大桥声屏障设计为研究对象,结合北大桥交通噪声污染调查分析,阐述了声屏障高度、声屏障结构形式等声屏障设计治理方案,并从规划阶段、运营阶段等方面探讨了城市桥梁交通噪声的控制对策。     

首尔交通改善经验与生态交通发展模式

摘要：本文从轨道交通网、地面公交网、城市道路网、行人空间网、自行车道网和生态交通网六个方面对首尔的交通改善措施与经验进行分析,挖掘其中包含的先进交通理念,期冀对我国城市交通改善起到抛砖引玉的作用。     

九江市中心城区道路交通问题剖析及对策建议

城市交通是城市发展的支柱,城市道路交通发展从某种意义上可以制约或促进整个城市的发展方向.从城市道路交通的角度分析现阶段九江市中心城区道路交通系统存在的问题,提出使近期交通改善与城市总体规划和谐衔接,促进中心城区良性滚动发展的对策建议.     

临时关闭道路以疏导城市道路交通流的可行性分析

文章基于Braess悖论,以单位车辆的平均出行时间为最优目标,以网络道路系统为约束条件,从逆向思维角度建立了通过临时关闭道路引导交通流以缓解城市道路交通拥挤的Narsh均衡非线性规划模型,并以北京二环道路网络为研究对象进行了实例分析。结果表明,在城市道路网中,关闭部分路段并不能明显缓解交通拥堵现状,但可以在不影响路网整体通行时间的条件下改善路网局部拥堵状况。建议城市道路交通临时疏导方案应该根据路网交通流的分布特点和道路通过能力等因素进行制订。     

Congestion avoidance in city traffic

The number of vehicles on the road (worldwide) is constantly increasing, causing traffic jams and congestion especially in city traffic. Anticipatory vehicle routing techniques have thus far been applied to fairly small networked traffic scenarios and uniform traffic. We note here a number of limitations of these techniques and present a routing strategy on the assumption of a city map that has a large number of nodes and connectivity and where the vehicles possess highly varying speed capabilities. A scenario of operation with such characteristics has not previously been sufficiently studied in the literature. Frequent short‐term planning is preferred as compared with infrequent planning of the complete map. Experimental results show an efficiency boost when single‐lane overtaking is allowed, traffic signals are accounted for and every vehicle prefers to avoid high traffic density on a road by taking an alternative route. Comparisons with optimistic routing, pessimistic routing and time message channel routing are given. Copyright © 2014 John Wiley & Sons, Ltd.     

Study on road section environmental traffic capacity model and algorithm under double constraints

The coordinated development of city traffic and environment is a key research content in traffic field in twenty-first Century. Among them, road section environmental traffic capacity analysis is one of the important research issues. It can provide solid theoretical basis and reliable data support for road network traffic optimization control, road traffic pollution control and city traffic structure optimization. This paper analyzed main factors which impacted environmental traffic capacity from two aspects, including road capacity constraint conditions and road traffic pollution control constraint conditions. Then, road section environmental traffic capacity optimization model was established, and method of improved augmented Lagrange function was used to solve the model. Case study showed that, (1) The environmental traffic capacity optimal model and methodology were effective; (2) In order to ensure road section environmental traffic capacity greater than (or equal to) road capacity, some measures could be taken including adjusting motor vehicle type proportion as well as improving emission characteristics of motor vehicles exhausting pollutants.     

Tackling traffic congestion in Accra,Ghana: A road user's perspective

A fast emerging component of the urban transportation problem in cities of the Third World is the problem of traffic congestion. Rapid increases in car ownership coupled with poor land use planning, inadequate road space, lack of regulated parking systems, uneducated use of the road by pedestrians, and bad driving behavior of motorists have all combined to produce congestions comparable to those experienced in cities in the advanced parts of the world. Traffic management measures have been tried in some of the major cities such as road expansion and redistribution of land uses in city centers, but most have produced minimal results. It is recommended in this paper that city authorities adopt an integrated approach to congestion with emphasis on influencing the behavior of the road users.     

广州市道路交通规划建设探讨

文章针对广州市道路系统规划的基本状况及存在的问题,结合国外城市道路交通规划建设及管理经验,提出了基于小尺度道路网、合理道路等级级配和快速路系统的城市道路交通规划建设优化措施及建议,为缓解城市交通拥堵提供理论依据。     

Road pricing — should and might it happen?

This article discusses recent attempts to implement a federally sponsored road pricing demonstration in the United States. It examines reasons for the attempts, pointing to several enduring traffic related problems; the greater effectiveness and flexibility of road pricing compared to other measures; and the proven feasibility of area licenses as in Singapore. The generally negative reaction of city decision-makers to road pricing is specified, particularly concerns about harm to businesses, interference with the right to travel and discrimination against the poor. Some lessons for further attempts at implementation of road pricing include more attention to contingency planning for worst possible outcomes; the design of parking permit programs which might lead the way to road pricing; and the selection of recreational rather than downtown sites for first attempts at innovative parking permit and road pricing schemes.     

A robust approach for road users classification using the motion cues

Video monitoring of traffic is a common practice in major cities. The data generated by video monitoring has practical uses such as traffic analysis for city planning. However, the usefulness of video monitoring of traffic is limited unless there is also a reliable way to automatically classify road users. This paper presents an automated method of road users’ classification into vehicles, cyclists, and pedestrians by using their motion cues. In this method, the movement of road users was captured on sequences of video frames. The videos were analysed using a feature-based tracking system, which has returned the tracks of road users. The separate pieces of information gained from these tracks are hereafter called Classifiers. There are nineteen classifiers included in this method. The classifiers’ values were assessed and integrated into a fuzzy membership framework, which in turn required prior configurations to be available. This led to the final classification of road users. The performance of this method demonstrated promising results. An important contribution of this paper is the creation of a robust approach that can integrate different classifiers using fuzzy membership framework. The developed method also uses parametric classifiers, which do not depend on the specific geometry or traffic operation of the intersection. This is a key advantage because it enables transferability and improves the practicality and usefulness of the method.     

Analyzing spatiotemporal traffic line source emissions based on massive didi online car-hailing service data

Nowadays, the massive car-hailing data has become a popular source for analyzing traffic operation and road congestion status, which unfortunately has seldom been extended to capture detailed on-road traffic emissions. This study aims to investigate the relationship between road traffic emissions and the related built environment factors, as well as land uses. The Computer Program to Calculate Emissions from Road Transport (COPERT) model from European Environment Agency (EEA) was introduced to estimate the 24-h NOx emission pattern of road segments with the parameters extracted from Didi massive trajectory data. Then, the temporal Fuzzy C-Means (FCM) Clustering was used to classify road segments based on the 24-h emission rates, while Geographical Detector and MORAN’s I were introduced to verify the impact of built environment on line source emissions and the similarity of emissions generated from the nearby road segments. As a result, the spatial autoregressive moving average (SARMA) regression model was incorporated to assess the impact of selected built environment factors on the road segment emission rate based on the probabilistic results from FCM. It was found that short road length, being close to city center, high density of bus stations, more ramps nearby and high proportion of residential or commercial land would substantially increase the emission rate. Finally, the 24-h atmospheric NO₂ concentrations were obtained from the environmental monitor stations, to calculate the time variational trend by comparing with the line source traffic emissions, which to some extent explains the contribution of on-road traffic to the overall atmospheric pollution. Result of this study could guide urban planning, so as to avoid transportation related built environment attributes which may contribute to serious atmospheric environment pollutions.     

Analysis of the optimal length of road expansion – A case study of the Taipei metropolitan area

This study explores the optimal investment in the length of an expanded section of road to mitigate the congestion on a transportation corridor. It is assumed that one end of the road is in the central business district (CBD) and that the households are uniformly distributed along the road. Each individual makes trips from his/her residence to the CBD. Trip demand is elastic and depends on the cost of the trip (including congestion costs). During the first stage, the government determines the length of the expanded section given the width of that section. In the second stage, road users determine their trip demands by taking into consideration the trip cost function. In the process of solving this problem, the equilibrium traffic volume is first solved using differential equations. The optimal length of the expanded section is then solved by maximizing the social welfare. The analysis is then applied to the case of the Tucheng city – Banciao city – Taipei CBD corridor in the Taipei metropolitan area. The scheme of road expansion without tolling performs closely to the first-best scheme for the case of a high potential demand. This study’s approach can serve as valuable reference for city planners engaged in road planning in a transportation corridor between the CBD and satellite cities in a metropolitan area.     

A traffic noise model for road intersections in the city of Cartagena de Indias,Colombia

Road traffic noise models are fundamental tools for designing and implementing appropriate prevention plans to minimize and control noise levels in urban areas. The objective of this study is to develop a traffic noise model to simulate the average equivalent sound pressure level at road intersections based on traffic flow and site characteristics, in the city of Cartagena de Indias (Cartagena), Colombia. Motorcycles are included as an additional vehicle category since they represent more than 30% of the total traffic flow and a distinctive source of noise that needs to be characterized. Noise measurements are collected using a sound level meter Type II. The data analysis leads to the development of noise maps and a general mathematical model for the city of Cartagena, Colombia, which correlates the sound levels as a function of vehicle flow within road intersections. The highest noise levels were 79.7 dB(A) for the road intersection María Auxiliadora during the week (business days) and 77.7 dB(A) for the road intersection India Catalina during weekends (non-business days). Although traffic and noise are naturally related, the intersections with higher vehicle flow did not have the highest noise levels. The roadway noise for these intersections in the city of Cartagena exceeds current limit standards. The roadway noise model is able to satisfactorily predict noise emissions for road intersections in the city of Cartagena, Colombia.     

南宁市白沙大桥北岸节点改造及其效果评价

文章以南宁市白沙大桥北岸节点改造设计为例,探讨城市道路平面交叉口改造设计的思路,同时从整体交通路网着眼,介绍采用交通仿真对改造效果进行评价的方法。