Bi-level programming model for reconstruction of urban branch road network

Considering the decision-making variables of the capacities of branch roads and the optimization targets of lowering the saturation of arterial roads and the reconstruction expense of branch roads, the bi-level programming model for reconstructing the branch roads was set up. The upper level model was for determining the enlarged capacities of the branch roads, and the lower level model was for calculating the flows of road sections via the user equilibrium traffic assignment method. The genetic algorithm for solving the bi-level model was designed to obtain the reconstruction capacities of the branch roads. The results show that by the bi-level model and its algorithm, the optimum scheme of urban branch roads reconstruction can be gained, which reduces the saturation of arterial roads apparently, and alleviates traffic congestion. In the data analysis the arterial saturation decreases from 1.100 to 0.996, which verifies the micro-circulation transportation's function of urban branch road network.

Evaluating the Feasibility of Road Diets for Advancing Urban Mobility in Newark, DE

Road Diets are far from a new technique for designers to apply to roadways. Yet after over 50 years of implementation and countless studies into their effectiveness, it is only relatively recently that the process is gaining widespread recognition and implementation. Each year, more states and countries are examining potential road diets and putting them into place. Still, there remains great skepticism and opposition in many corners. In addition, cities and states may be drawing from many of the same sources in how to go about the process of a road diet and evaluate them, yet their methodology, goals, and even terminology can vary from region to region. This study analyzes the implementation of a road diet along a one-way arterial road, in Newark, Delaware. The primary aim of this analysis is to evaluate the feasibility of introducing a dedicated bicycle infrastructure to enhance local accessibility and to quantify its potential impacts on traffic flow, parking availability, and loading logistics within the vicinity. While the reduction of one lane could be perceived as a constraint on traffic management, the investigation revealed that E Main Street, the roadway analyzed, for the most part, can adequately accommodate its traffic load with a single lane. Detailed findings underscore the notable enhancement in level of service and subsequent reduction in delay times across most surveyed approaches.

Mechanisms for Cross-Scaling, Flexibility and Social Learning in Building Resilience to Sea Level Rise: Case Study of Hampton Roads, Virginia

This case study examines how the Hampton Roads Sea Level Rise Preparedness and Resilience Intergovernmental Planning Pilot Project, a whole-of-government and whole-of-community approach to planning for and adapting to sea level rise, addressed coastal resilience in a southeastern Virginia watershed that spans multiple jurisdictions. Meeting the challenge of sea level rise requires that actors across multiple sectors—citizens, community organizations, industry and government—understand the risks and work together to make critical decisions regarding adaptation strategies and actions. The case study area includes Little Creek Amphibious Base, which is bordered by the cities of Norfolk and Virginia Beach. Adaptation responses to sea level rise by the military base and the local governments will impact each other and the residents of the area, but no cooperative agreements are in place for a joint or collaborative response. This case study examines public and private infrastructure at risk, the infrastructure interdependencies, and mechanisms for providing collaborative solutions. Engagement of area residents and other stakeholders is also integral to the process of adaptation, which includes educating about sea level rise risk and provides a mechanism for social learning that enables stakeholders to participate in critical adaptation decisions. The case study demonstrates a method to improve resiliency in the case study area and inform a regional, multi-sectoral response to sea level rise adaptation strategies.

基于改进DeeplabV3+的遥感图像道路分割模型

针对遥感图像道路分割边界模糊和遮挡难以区分的问题,提出了基于改进DeeplabV3+的遥感图像道路分割模型。该模型在主干网络中引入MobileNetV3和高效通道注意力机制(ECA),减少了参数量并关注连续的道路特征信息。在解码过程中采用多级上采样,增强了编码器和解码器之间的紧密连接,全面保留了细节信息。同时,在ASPP模块中采用深度可分离膨胀卷积DS-ASPP,显著减少了参数量。实验结果表明,该模型在Massachusetts Roads数据集上的交并比达到了83.71%,准确率达到了93.71%,分割精度最优,模型参数量为55.57×10^(6),能够有效地避免边界模糊和遮挡导致的错漏检问题,在遥感道路分割中提高了精度和速度。

市域铁路调度中心级路网综合监控系统设计

文章研究了市域铁路调度中心级路网综合监控系统设计,在明确市域铁路特点以及调度功能需求的基础上,从系统总体定位、系统设计原则、系统功能设计、系统主要构成、软硬件设计等方面出发,分析了综合监控系统设计要点,有利于减少路网运行风险,提高线路资源的集中监控和整合利用水平,推动市域铁路实现更高质量的发展。

占道施工影响下区域路网容量计算与关键路段识别方法

为研究占道施工事件对区域路网络容量的影响,基于双层规划理论,构建了考虑路段通行能力约束的区域路网络容量计算模型,并设计了求解算法。通过VISSIM仿真软件,确定了施工区段通行能力基准值,对实际通行能力与各影响因素之间的定量关系进行分析,给出了占道施工条件下实际通行能力计算方法。结合交通流分配结果、边介值、蓄意破坏前后路网效率变化率给出了占道施工期区域关键路段识别方法。最后以哈尔滨市阿城区的路网为案例,通过手机信令数据获取得到出行需求分布,计算占道施工前后的路网容量,并对占道施工期阿城区路网进行了重要度排序。研究表明:初始条件下区域路网络容量为38 445 pcu/h,施工时为36 865 pcu/h,路网络容量值减少了4.1%。

市政道路平面交叉口的优化设计要点

市政道路平面交叉口是城市交通系统的重要组成部分,直接影响交通运行效率、安全性及出行的便捷性。随着城市化进程的不断推进,交通流量的增长使得交叉口的设计和优化成为解决交通拥堵问题和提高交通系统运行效率的关键。文章深入探讨了市政道路平面交叉口的优化设计要点,包括车道的优化扩展、非机动车和行人通行的安全保障、交叉口几何设计的优化,以及交通流量管理与拥堵缓解措施,为城市规划者和交通管理者提供了有益的指导,以改善城市的交通基础设施,提升出行体验,减少拥堵问题,从而为城市的可持续发展做出贡献。

城市道路信号平面交叉口合理间距研究

平面交叉作为城市道路的关键节点,其合理净距的取值直接影响到整条路段车辆的行车安全和通行效率。文章统计分析了平面交叉口由于间距过短所引发交通事故的原因,基于交通流理论、车辆加减速方式、统计学和概率论原理、驾驶员操作习惯等建立了平面交叉口合理间距的计算模型,得到不同设计速度、车道数情况下平面交叉口合理间距的取值。

运营公路高位崩塌危岩体监测技术研究现状浅析

崩塌地质灾害受到地形条件约束,一般在峡谷地带尤其发育。地形陡峻、沟谷深切,加之强烈的风化作用影响,导致运营公路在峡谷路段安全风险剧增。该文通过文献调研简述了崩塌地质灾害的成因类型,总结为倾倒式、滑移式、错断式、拉裂式和鼓胀式五类;危岩落石的运动特征复杂,受地形条件控制表现出崩落、跳跃、滚动、抛散等形式。该文分析了高位危岩对公路设施的危害及其特点,论述了当前崩塌危岩体监测的主要技术手段及其优越点。基于该领域的研究现状,初步提出了适用于运营公路高位危岩的监测思路:无人机贴近倾斜摄影测量快速识别→危岩体与监测区段划分→视频/激光雷达图像识别监测→监测预警与应急处置。该文提出的监测思路旨在崩塌发生后迅速预警,可有效应对次生灾害的发生,减少灾害造成的进一步损失,赢得抢通救灾的宝贵时间,对山区公路类似情况具有一定的参考价值。

高地下水位条件下低路堤路基性能状态演化研究

通过水准仪观测以及传感器监测等方法对高水位条件下低路堤路基的湿度、土压力及沉降进行监测。结果表明,土体湿度、土压力及沉降受周围环境、气候条件及周边土体影响,平衡时湿度接近30约为30%,5个月后土压力趋于稳定,土压力值约为22.7 kPa,8个月后路基沉降趋于稳定,沉降值约为8.34 mm。低路堤路基技术在应用时应做好隔水措施。

路网级桥梁集群监测系统建设关键技术及实践

桥梁健康监测是防范结构运行风险、提升养护管理和应急处置水平的重要举措之一,国家和行业政策对于桥梁结构健康监测系统建设提出了明确的要求。以广东交通集团路网节点桥梁集群监测系统为例,介绍了路网级桥梁监测系统的技术路线、总体架构、关键技术和建设实践,可为地市级、路网级桥梁健康监测系统的构建提供参考。

推进天河区市政道路工程高质量建设研究

通过推进市政道路工程高质量建设、提高城市交通出行品质的研究,对天河区的道路进行系统梳理、深入剖析,确定一批确需品质提升的项目,全面提升城市出行品质,同步总结过程经验,指导后续项目建设,强化始终时候管理,加强项目完工后养护,确保良好使用品质。

基于激光点云数据的室内路网构建方法

面对价格昂贵的专业级三维激光扫描仪,针对使用现有二维底图或人工建模可能使得在构建跨楼层路网的过程中出现准确性或效率性低等情况,且考虑如何对室内过道、走廊等区域进行抽象,提出一种基于激光点云数据的室内路网构建方法。该方法以消费级激光雷达扫描设备采集的建筑物内部点云为基础数据,结合直通滤波和投影滤波对点云进行预处理,得到去噪后的平面二维点云,进行栅格二值化处理,针对性填充点云孔洞,抽取骨架线,剔除毛刺并提取骨架线节点,将节点间的拓扑关系存储为邻接表形式的图模型,得到可利用Dijkstra算法寻径并将寻得的最短路径可视化的三维路网模型。

道路网络多阶段抗灾能力优化模型构建与应用

为了降低路网抗灾成本并保障路网快速连通,研究道路交通网络多阶段灾害应对能力优化的问题.建立综合灾前应急工作站点选址和灾后路网恢复决策的3层规划模型,其中特别考虑了应急救援设施和后勤保障资源在耗尽性、运输方式和恢复作用上的差异,定量建模了两者间的相互协作关系.通过综合双层遗传算法和FrankWolfe算法,获得模型的近似最优解.研究结果表明,与未考虑灾后恢复过程的灾前布设决策和未考虑后勤保障资源的灾前布设决策相比,最优决策可以分别降低10.96%的后勤保障资源运输成本和11.51%的加权恢复成本.后勤保障资源和应急救援设施布设数量共同影响路网的恢复效果,忽略两者间的协作关系,将会高估应急救援设施布设数量增加对恢复效果的影响.

Road Impacts on Spatial Patterns of Land Use and Landscape Fragmentation in Three Parallel Rivers Region,Yunnan Province,China

The structure and function of network is a central issue in landscape ecology.Road networks with hierarchical structure are crucial for understanding landscape dynamics.In this study,we compared the distribution of national road,provincial road,county road and rural road in the Three Parallel Rivers Region(TPRR)in Yunnan Province of China,and estimated the effect of roads(and other factors)on the spatial patterns of land use and land cover with logistic regression.In addition,we analyzed the land use and land cover change(LUCC)and landscape fragmentation in 1989–2005 along a buffer zone of the primary traffic corridor,national road G214.The results showed that,county and rural roads had much higher percentage of length extending into more natural habitats at higher elevation and steeper slope,compared with the higher level roads in this region.While the distributions of natural land cover types were dominated by environmental factors,human land use types i.e.,building land and farmland types were significantly related with roads,linking more closely with lower level roads.The LUCC dynamics(1989–2005)of the G214 buffer zone showed a general trend of land transformation from conifer forests and valley arid shrubs to building land and farmland,and from ice and snow to alpine shrubs and forests.With the length of G214 unchanged during the time,the overall landscape pattern changed little in the buffer zone,but habitat fragmentation and area decrease had occurred for the natural vegetation types,in contrast to patch mergence and expansion of human land use types,and landscape fragmentation was intensified above 2500 m a.s.l.but declined below the elevation.The results indicated the dynamics of landscape composition and patch type level distribution in spite of the stability of the overall landscape pattern,and implied the potential role of roads,especially the low level roads on landscape changes.

双高计划背景下路桥专业人才培养路径及其优化对策

从行业、企业、学校、毕业生几方面对双高计划背景下路桥专业人才培养路径进行分析。结果表明,从行业方面来看,路桥行业的人才需求广泛且多元化,与各城市的具体发展策略和基础设施建设需求紧密相关。从企业方面来看,市场对具备专业技术、管理能力及高级维护技术的专业人才有明显需求。从学校方面来看,道路与桥梁工程技术专业毕业生就业方向多元。从毕业生方面看,78.57%的毕业生具备较强的专业技能和扎实的理论知识基础,13.70%的毕业生反映存在技能与岗位不匹配的问题。为培养出更多高素质、业务熟练的路桥专业人才,需深化产教融合,优化课程设置,加强与地方需求的对接,提升就业服务质量,强化对新技术的学习,建立持续学习机制。

高速铁路捎带模式下公铁联运适用范围及其影响因素特征分析

高铁快运作为一种新型运输模式,可有效减少公路运输造成的环境污染,在促进高附加值、小批量货物运输的可持续发展方面具有重要意义。利用高速铁路富余能力组织快件“捎带运输”有着巨大发展空间,如何发挥公铁联运优势并优化高铁快运模式决策成为亟待解决的关键问题。据此,以运输成本最小化为目标,建立高速铁路捎带下公铁联运和公路运输2种模式的成本分析模型,并进一步分析模式选择的适用范围。以哈大高速铁路为例,分析2种运输模式的成本与影响因素特征,将不同站点环境下货车晚点到站对模式选择影响的风险等级进行划分,可为快递运输公司快件集疏运模式选择提供决策参考。

Effects of geometric design of forest road and roadside vegetation on traffic noise reduction

Geometric design of forest roads and design of their landscapes can reduce noise pollution and its harmful effects on human health. We investigated the effects of technical and biological parameters such as geometric road design and various roadside tree stands on reducing noise pollution according to the tree density and distance from roadway in Darabkola Forests, Sari, Iran. We recorded the noise generated by a car （Land Rover） relative to changes in longitudinal slope, horizontal curve radius and type of road pavement. We also measured noise levels according to roadside tree density and stand type （coniferous and hardwood） in 40 rectangular plots of three widths （25, 100 and 300 m） and 50 m length that were randomly demar- cated along forest roads. The changes in noise level were recorded using a decibel meter with an accuracy of q-1.5 dB and resolution of 0.1 dB. Noise levels were higher alongside unpaved roads than alongside paved roads. There was an inverse relationship between the measured noise level and horizontal curve radius. The rate of noise level on horizontal curve with a radius less than 30, 30-45 m and more than 45 m were 64.8, 70.8 and 75.9 dB, respectively. The noise level increased with the increasing longitudinal slope of the road. There was a significant difference between the noise level on slopes less than 3 % （67 dB） and 3-8 % （71.2 dB） in comparison with slopes greater than 8 % （77.8 dB）, （p 〈 0.05）. Pinus brutia L. reduced the noise level more （about 6 dB） in stands of 1/3 density of mixed hardwoods within 25 m from middle of the road. Careful design of geometric properties of forest roads as well as planting coniferous trees with hardwoods is a suitable solution for reducing noise pollution.

Determination of critical parameters in the analysis of road tunnel fires

The analysis of the fluid characteristics downstream of a fire source in transportation tunnels is one the most important factor in the emergency response, evacuation, and the rescue service studies. Some crucial parameters can affect the fluid characteristics downstream of the fire. This research develops a statistical analysis on the computational fluid dynamics(CFD) data of the road tunnel fire simulations in order to quantify the significance of tunnel dimensions, inlet air velocity, heat release rate, and the physical fire size(fire perimeter) on the fluid characteristics downstream of the fire source. The selected characteristics of the fluid(response variables) were the average temperature, the average density, the average viscosity, and the average velocity. The prediction of the designed statistical models was assessed; then the significant parameters' effects and the parameters interactive effects on different response variables were determined individually. Next, the effect of computational domain length on the selection of the significant parameters downstream of the fire source was analyzed. In this statistical analysis, the linear models were found to provide the statistically good prediction. The effect of the fire perimeter and the parameters interactive effects on the selected response variables downstream of the fire, were found to be insignificant.

Analysis of Road Traffic Noise Pollution around a University in Binzhou

The number of automobiles in the urban area of Binzhou City continues to increase,and traffic noise pollution is increasingly serious. In this study,noise pollution on Huanghe 5 Road near the south gate of Binzhou University was monitored. The results showed that the road noise pollution on Huanghe 5 Road was relatively serious on the whole,especially in the peak periods of traffic flow in the morning and afternoon,because the increase in the number of pedestrians brought inconvenience to traffic,thereby resulting in an increase in car whistle.