城市道路检查井周边下沉、病害原因分析及建议

以某市为例,详细调查道路检查井存在的病害种类,从井盖、井体和基础(表层与深层)剖析其病害成因,对于完善检查井病害形成机理,科学制定针对性强的对策,提高市政道路检查井的适用性具有积极意义。

缅甸其培市道路改造设计与施工

通过对缅甸其培市道路改造设计,论述了其培道路选线设计、水泥路面厚度设计的方法及设计指标,并简单介绍了施工步骤,效果良好。

抗车辙剂在城市主干路沥青路面施工中的应用研究——以栖霞区马高路北延道路建设工程为例

为解决城市道路的车辙问题,节约养护维修成本,延长道路使用寿命,围绕抗车辙剂作用机理、抗车辙沥青混合料配合比设计以及施工工艺等方面展开了抗车辙剂在城市主干路沥青路面施工中的应用研究。研究结果表明:抗车辙剂的加入可以有效改善沥青混合料的高温抗变形能力;路面长期性能跟踪观测结果显示,掺加抗车辙剂的沥青路面具有更小的车辙深度以及更好的长期服役性能。抗车辙剂将在我国城市道路中具有广阔的应用场景。

市域道路交通突发事件应急资源调度路径分析

应急救援调度应在事故发生时,高效、及时、方便启动应急救援调度,从而使损失最小化,但在具体实施时,救援设备、救援队伍、救援路线等信息不能快速确定,造成人员生民安全和财产重大损失。文章以市域道路应急资源调度为背景,对各影响因素进行层次分析,运用最短路径的Dijkstra算法进行建模,求解市域交通路网应急资源调度最优路径。采用ArcGIS软件创建道路网络模型,利用Dijkstra最短路径算法对应急资源调度选择最优路径,提高应急救援能力的针对性,并结合实际案例,验证基于地理信息系统的公路应急资源调度最优路径的可行性,为市域道路交通应急资源调度最优路径选择提供决策支持。

市政道路改造中旧沥青路面就地冷再生施工技术

近些年来,随着城市的发展,市区车流量的增加,车辆行驶、水损坏等问题也对市政道路产生一定的危害。如不及时处理,会诱发交通事故或者导致道路的整体性能无法满足路用的相关要求。市政道路具有一定的特殊性,为了最大程度降低道路维修对交通造成的影响,近些年沥青路面的就地冷再生施工技术有了较大发展,在道路维护和维修等方面有了广泛的应用。本文主要介绍市政道路改造中旧沥青路面就地冷再生施工技术方面的内容,希望能对类似工程起到借鉴作用。

交通部关于开展道路运输企业安全生产专项整治工作的通知

各省、自治区、直辖市交通厅(局、委),新疆生产建设兵团交通局:为贯彻落实《国务院关于进一步加强安全生产工作的决定》精神,按照全国道路交通安全工作部际联席会议第一次会议和《预防道路交通事故"五整顿""三加强"实施意见》的有关要求,进一步加强道路运输企业的安全生产工作,从源头上预防和减少道路运输事故,针对当前道路运输安全生产的严峻形势。

The Landscape Design of Roads Afforestation of Jiangnan New District in Mudanjiang Municipality

Based on road characters in Jiangnan New District in Mudanjiang Municipality,four typical roads were selected to carry out road afforestation design with consideration of local building features and local vegetations,in order to integrate both of landscape effects,in terms of improving and beautifying city environment,and of ecological effects,such as filtering air,reducing temperature,increasing humidity,and reducing noise.

A GIS-based Spatial Analysis of Housing Price and Road Density in Proximity to Urban Lakes in Wuhan City, China

As one of the essential urban open spaces, lakes usually contribute immensely to the quality of residents′ daily lives. Different from hedonic approach employed in existing researches on urban open spaces in China, this paper integrates housing price surface with road density to analyze the spatial characteristics in proximity to urban lakes in Wuhan City, China. With the expansion of Wuhan City, urban lakes became polluted, they shrunk or even disappeared, leading to unfavorable conditions for sustainable development of the city. To better understand the spatial relationship between the city and lakes, we classify the urban lakes in Wuhan central area into ′lakes in the urban center′ and ′lakes in urban fringe′. Based on housing price surface we explore the spatial characteristics in proximity to different lakes and differences between the lakes. We also use Geographic Information System(GIS) tool to calculate road density as a supplementary indicator to reflect the accessibility in proximity to urban lakes. The results indicate that relative independence exists between different towns, and the spatial characteristics are different depending on scales and locations. In most of cases, the road density is lower where closer to the lakeshore while the housing price exhibits an opposite pattern. We conclude that city governments and urban planners should give more considerations to these spatial differences, somewhere should be better planned and protected as an important waterfront and somewhere the control of unreasonable real estate development nearby should be strengthened.

Role of street patterns in zone-based traffic safety analysis

Although extensive analyses of road segments and intersections located in urban road networks have examined the role of many factors that contribute to the frequency and severity of crashes, the explicit relationship between street pattern characteristics and traffic safety remains underexplored. Based on a zone-based Hong Kong database, the Space Syntax was used to quantify the topological characteristics of street patterns and investigate the role of street patterns and zone-related factors in zone-based traffic safety analysis. A joint probability model was adopted to analyze crash frequency and severity in an integrated modeling framework and the maximum likelihood estimation method was used to estimate the parameters. In addition to the characteristics of street patterns, speed, road geometry, land-use patterns, and temporal factors were considered. The vehicle hours was also included as an exposure proxy in the model to make crash frequency predictions. The results indicate that the joint probability model can reveal the relationship between zone-based traffic safety and various other factors, and that street pattern characteristics play an important role in crash frequency prediction.

Integrated reliability of travel time and capacity of urban road network under ice and snowfall conditions

In order to evaluate and integrate travel time reliability and capacity reliability of a road network subjected to ice and snowfall conditions,the conceptions of travel time reliability and capacity reliability were defined under special conditions.The link travel time model(ice and snowfall based-bureau public road,ISB-BPR) and the path choice decision model(elastic demand user equilibrium,EDUE) were proposed.The integrated reliability was defined and the model was set up.Monte Carlo simulation was used to calculate the model and a numerical example was provided to demonstrate the application of the model and efficiency of the solution algorithm.The results show that the intensity of ice and snowfall,the traffic demand and supply,and the requirements for level of service(LOS) have great influence on the reliability of a road network.For example,the reliability drops from 65% to 5% when the traffic demand increases by 30%.The comprehensive performance index may be used for network planning,design and maintenance.

Road Centrality and Landscape Spatial Patterns in Wuhan Metropolitan Area,China

Road network is a corridor system that interacts with surrounding landscapes,and understanding their interaction helps to develop an optimal plan for sustainable transportation and land use.This study investigates the relationships between road centrality and landscape patterns in the Wuhan Metropolitan Area,China.The densities of centrality measures,including closeness,betweenness,and straightness,are calculated by kernel density estimation(KDE).The landscape patterns are characterized by four landscape metrics,including percentage of landscape(PLAND),Shannon′s diversity index(SHDI),mean patch size(MPS),and mean shape index(MSI).Spearman rank correlation analysis is then used to quantify their relationships at both landscape and class levels.The results show that the centrality measures can reflect the hierarchy of road network as they associate with road grade.Further analysis exhibit that as centrality densities increase,the whole landscape becomes more fragmented and regular.At the class level,the forest gradually decreases and becomes fragmented,while the construction land increases and turns to more compact.Therefore,these findings indicate that the ability and potential applications of centrality densities estimated by KDE in quantifying the relationships between roads and landscapes,can provide detailed information and valuable guidance for transportation and land-use planning as well as a new insight into ecological effects of roads.

Traffic Calming in Quebec： Speed Humps and Speed Cushions

Speed management is an essential tool in ensuring the improved safety of users of urban roads, particularly vulnerable users. It relies on several measures： awareness campaigns, speed control, as well as the development and operation of the road infrastructure. Municipalities in Quebec are increasingly resorting to the development of traffic calming measures, and are facing numerous questions concerning their installation and their effectiveness. To respond to this need, the ministere des Transports du Quebec （Quebec Department of Transport） has begun publishing a series of fact sheets on a variety of traffic calming measures, including speed humps and speed cushions, raised crosswalks and intersections, neckdowns, centre islands and chicanes. A general fact sheet introduces all of the measures and notably outlines the procedure for pre-implementation analysis. Each fact sheet dedicated to an individual measure outlines the implementation context, advantages and disadvantages, geometric characteristics, effectiveness at reducing speed, and maintenance requirements, including winter maintenance. Two fact sheets are already published： the general fact sheet and the fact sheet on speed humps and speed cushions. The fact sheets as well as examples of measures implemented in municipalities are available on the minist6re＇s web site under Partenaires-Municipalites-Securite routiere.

Energy Savings in Municipal Road Lighting： The Case of the Municipality of Hersonissos

In an era governed by economic crisis, deep recession and lack of funds, the perspective of sustainable development drives local government to a more focused and constant effort to adapt to their daily requirements not only in respect to the central state but also towards the growing needs of the local society. As the need for planning actions in accordance with the principles of sustainable energy remains urgent, municipalities continue to envision and to respond to their role in helping to create a better future for generations to come. Thereupon the vision of the Municipality of Hersonissos, as firstly recorded in its Business Plan for 2011-2014, was, and still is, its＇ development in an Economic, Tourist and Cultural pole by adopting and applying the basic principles of sustainable development. At the same time the Municipality＇s rigid vision, planning, and evaluation, oriented by environmental protection, highlighted the need for networking on European level as although cities are different, their problems are often common. Thus on April 18, 2011, the Municipality of Hersonissos, joined the European Union initiative ＂Covenant of Mayors＂ [1] with the common aim of the fight against climate change. This article presents the significant initiatives taken in this direction in the last decade and their results not only on economical level but also along their social impact. It also aims to point out a municipality＇s vital role in knowledge and technology diffusion within the local society as sustainable energy development can be deployed not only by the private sector but also by the public.

Operation reliability for on-ramp junction of urban freeway

A disorder situation of traffic operation always appears in on-ramp junction area of urban freeway,because the operation action for vehicles presents the weaving condition,especially for different vehicle types.Based on the analysis on the cellular automata theory,and combining with on-site survey data,several key parameters were defined,namely,cellular length,cellular speed,cellular acceleration,updating time interval.In addition,cellular acceleration rule,cellular deceleration rule,random rule,lane-changing rule and other micro-simulation rules were set,and cellular automaton micro-simulation model was set up.Further-more,a micro-simulation module was developed for traffic operation actions of on-ramp junction with Matlab toolbox.Finally,a simulation experiment for traffic operation reliability was done with this micro-simulation module,and the situation of change for on-ramp junction area was obtained under the conditions of different mainline design speed,acceleration lane length,vehicle generation probability and lane-changing probability.The results show that operation reliability for on-ramp junction is determined by the parameters of the probability of vehicle generation and the length of acceleration lane,especially for on-ramp.

Capacity models on expressway near a bus bay stop with an access

To determinate the expressway capacity near a bus bay stop with an access, capacity models on the expressway near a bus stop with an access were developed on the basis of gap acceptance theory and queuing theory. Depending on a bus stop position to an entrance or an exit ramp, the capacity models were developed for four cases. Bus bay stops with overflow and bus bay stops without overflow were considered. A comparison of simulation experiment and model calculation was carried out. Results show that the suggested models have high accuracy and reliability, at bus arrival rate below 60 vehicles per hour(veh/h) or vehicle volumes at the entrance and the exit below 200 passenger cars units per hour(pcu/h), and there are no significant difference in the capacities for four cases. When bus arrival rate is above 240 veh/h, the capacities of all four cases will decline rapidly. With berth number increasing, the increasing of the capacities is no obvious for four cases. As the bus arrival rate and vehicle volumes at the entrance and the exit increase, bus stops located downstream of an entrance and upstream of an exit have a remarkably effect on the capacities. The latter case is much heavier than the former. Those results can be used to traffic design and optimization on urban expressway near a bus stop with an access.

Joining Paths and Dividing Paths： Juiz de Fora, Brazil

The aim of this paper is to present the urban history of Juiz de Fora, a city with some 500,000 inhabitants in southeastern Brazil, and discuss how strategic decisions about the planning and construction of roads and highways can determine ways of life in a city. While paths may integrate landholdings and territories, they may also segregate communities and environments, causing deep rifts in the fabric of urban and land areas. The growth of Juiz de Fora is particularly marked by the construction of paths. This article reviews the local urban history from the establishment of paths in the city, to an analysis of the major impact and benefits they have had, notably on the local economy and demographics, as well as on the conservation of the local environment： Issues that are frequently relegated to a secondary role in the cost-benefit analysis of the city＇s planning decisions. After analysis of the case study, the authors concluded that citizens should be included on the agenda of the city, from spectators to actors of daily urban life.

Dynamic evaluation of traffic flows on city roads

This paper presents an analysis of the random fluctuations, deferred conduction effect and periodicity of road traffic based on the basic features of road networks. It also discusses the limitations of road network evaluation theories based on road "V/C". In addition, it proposes a set of theoretical and technical methods for the real-time evaluation of traffic flows for entire road networks, and for solving key technical issues, such as real-time data collection and processing in areas with no blind zones, the spatial-temporal dynamic analysis of road network traffic, and the calibration of key performance index thresholds. It also provides new technical tools for the strategic transportation planning and real-time diagnosis of road traffic. The new tools and methodology presented in this paper are validated using a case study in Beijing.

Pathological Manifestations on Concrete Bridges at Recife＇s Metropolitan Area

Bridges are structures being used to cross rivers, lakes or any other obstacles which involve water. These instruments are commonly used in cities like Recife, which consists of several islands. However, it is common in this city to observe the fast deterioration of these structures that have been built for decades and are subjected to structural recoveries only when they present a possible imminent collapse. The maintenance of these constructions, often used as tourist spots, is essential because of the economic importance, while these structures are responsible for transporting people and cargo, and also play a key role in the city＇s roads. This paper aims to present and assess the conservation status of these bridges through the study of possible pathologies found at Princesa Isabel Bridge, Government Agamenon Bridge, Ponte Giratória Bridge and Paulo Guerra Bridge. The methodology for its inspection will be prescribed by ABNT NBR-9452/86, which provides for ＂Surveys of Concrete Bridges/Viaducts＂. After analysis, it was found that most bridges problems were caused by the presence of moisture that accumulates in bridges due to the absence or malfunction of drainage systems.

Microscopic Fuzzy Urban Traffic Simulation with Variable Demand

Some microscopic traffic simulations on urban road network are developed up to now. However, the effect of urban transport policy in the local city is influenced with the complex interaction of automobile traffic and public transport traffic. Particularly, behaviours of vehicles should be described with the fuzziness of the subjective recognition and operation. On the other hand, the trip makers are influenced by various transport policies in terms of mode choice behaviour. The change in mode choice behaviour and number of public transport mode users would eventually affect traffic flow conditions on road network. Modal spilt and traffic conditions of a network are interrelated. Therefore, the present study mainly aims to integrate mode choice model and microscopic traffic simulation model based on fuzzy logic. In the study, the fuzzy logic based mode choice model is proposed. The proposed mode choice model and the existing microscopic traffic simulation model are combined. The developed model has been applied on real urban network to demonstrate the effectiveness of the installation of LRT system. Finally, it is helpful for evaluation of transport policy that the fuzzy logic based microscopic traffic simulation with modal choice model has been constructed.

Analysis on Influence Factors and Reduction Ways of Automotive Safety Cost

The paper introduces automotive safety cost formula, which defines the concept of private costs, technology costs and social costs and analyzes the impact of economic externalities in individual purchase decisions on urban traffic safety in the private costs and discusses the concept of hard and soft technology and its function to improve vehicle safety. Take people, vehicles and the environment as the main line and points out the promoting role of the relevant state departments, policy, research institutions and transportation infrastructure in the social cost for the entire transportation system security. Finally, about the security of car crash in low speed on urban roads, the paper gives some recommendations as for private costs, technology costs and social costs factor.