高速公路合理限速对策研究

基于对高速公路运营阶段交通流量的构成及增长分析,得出新建高速公路和非新建高速公路交通流量差异较大,交通特性明显不同,建议应采取不同的限速策略,并分别给出了合理的车速限制建议值。     

高速公路车速离散性与交通事故的关系及车速管理研究

对高速公路的车速标准差和亿车公里事故率的数据进行回归分析,建立了二者的关系模型,模型表明车速分布越离散,事故率越高,从而为高速公路的车速限制提供了理论依据。利用中国14条高速公路的地点车速调查数据,对15％位车速、85％位车速与单圆曲线的曲率变化率CCRs进行回归分析,分别建立了85％位车速与CCRs的回归模型以及15％位车速与CCRs的回归模型,利用这些模型提出了合理的基于交通安全的车速限制建议值。     

南通市国省干线公路安全保障工程研究

通过分析了南通市国省干线公路的交通事故特征及事故原因;提出了南通安保工程的治理方案,并对南通市的典型省道进行了效果评定,取得了良好的效果。     

车速限制技术及其在法国的进展

车辆限速行驶,将显地降低交通事故的发生量和危害性。“车速限制系统”是一种车载辅助驾驶设备,能帮助驾驶员更好地遵守道路车速限制,保障行车安全。本主要探讨“车速限制”技术的发展,并详细介绍了法国在“智能速度限制”研究领域的一项重要试验计划——LAVIA。     

高速公路加速车道上车辆的汇入模型

为了揭示高速公路合流区加速车道上车辆的运行规律，利用摄像机等观测仪器对中国许多省市高速公路合流区匝道车辆的汇入特征数据进行了大量调查。在对大量调查数据进行分析处理的基础上运用微分法建立了匝道车辆的汇入模型和行驶距离模型。该模型不但解释了调查结果，而且对高速公路规划设计、控制管理等工程实践有重要的指导意义。     

高速公路软土地基处理设计研究

软土地基处理是影响软土地区高速公路建设周期和建设投资的关键。大量的设计和施工实践经验,使得必须对高速公路软土地基处理规范中的一些规定做深入的思考。本文根据土体的物理性质,提出了软土、软粘土和非软土的完整分界,指出软土地基处理应以压实系数K≥0．85为下界;根据地质勘查报告,将出露的土层分为四大类,设计中应根据四类不同土层采取相应的地基处理方式;设计中总沉降计算受m取值和主固结沉降Sc影响较大,其计算值只供参考,不可作为施工方案选取的唯一标准;主固结沉降中不同计算方法所得结果差异较大,提出计算终结条件考虑以压实系数K≥0．85为标准更合实际且概念明确。文中所提的其他一些原则,在设计中必须予以考虑,以做到所提软基处理方案切实有效、又节省建设投资.     

基于决策树的高速公路事件持续时间预测

利用决策树方法对高速公路事件持续时间预测问题进行研究。首先在借鉴各国研究经验的基础上，根据所研究事件数据集中的事件持续时间数据的分布特征确定构造基于决策树的预测方法；然后用整理得到的660组事件数据，通过对各类事件的显著性分析，建立高速公路事件持续时间预测决策树，并用同一数据集中未用于决策树构造的170组数据对决策树的预测效果进行检验。检验结果表明：所开发决策树的预测值与实际值的相关系数为0．8423，预测结果基本能够反映真实的事件持续时间情况。     

湖南省高速公路限速标准调整综合效益评价

在研究湖南省高速公路新限速标准实施情况的基础上,结合已完成限速标志更换工作的常吉、常张、邵怀、怀新四条山区高速公路,从安全效益、社会效益和经济效益三个方面对限速标准进行了综合评价分析。得出实施新限速标准后,整体安全性能未发生明显变化,社会与经济效益显著。     

成渝高速客运的现状与思考

十年来成渝高速客运的发展对中国公路客车的发展起到了非常重要的作用。简述成渝高速客运的回顾、现状与思考。     

高速公路交通预测分配实用方法研究

基于现状高速公路交通分配预测方法的不足,提出了一种基于改进Dijkstra标号法的高速公路分配预测的实用方法。方法的研究分别从忽略公路交叉口转向阻抗和考虑公路交叉口转向阻抗的两种分配情况的优缺点出发,通过引入虚拟节点,建立改进的分配网络,由此基础上提出了改进的Dijkstra标号法。最后,通过一个网络分配实例验证,显示该方法具有较好的分配精度和可靠性。     

高速公路建设对热带雨林地区生态环境价值的损失分析

通过思小高速公路建设对自然保护区生态环境负影响带来的价值损失的定量化分析,在评价环境负影响的基础上,重点分析和筛选劣化指标,并结合思小高速公路现场的实际情况,采用影子工程的方法,建立指标与经济之间的关系,提出了计算其生态环境价值损失的公式,对热带雨林自然保护区的生态环境价值保护提出了定量依据.     

高速公路沥青路面发生水破坏的原因和防治措施

以往沥青路面设计、混合料组成设计和混合料施工3方面都被割裂开来,未进行综合考虑,致使沥青路面的早期水破坏很严重.针对上述3方面进行综合考虑,分析了水破坏的主要形式,讨论了引起水破坏的原因,提出了减少水破坏的主要措施.     

Evaluating the effectiveness of a smartphone speed limit advisory application: An on-road study in Port-Harcourt,Nigeria

The development of mobile phone applications that provide speed limit advice and warnings offers opportunities for use of the technology in the improvement of driver safety. This paper looks at the effect of an advisory Intelligent Speed Assistance (ISA) application on driver speeding behaviour. Twenty participants (all males within the age range of 35–60 years) completed a within-group experimental design. Participants drove in real traffic on a 46 km test route which incorporated three-speed limits zones (50 km/h, 60 km/h, and 80 km/h speed limits) and aggregated into 10 different segments. Compared with baseline levels, possible impacts of ISA system functionalities on driver behaviour were studied through appropriate metrics including cumulative speed distribution, mean speed, speed deviation, 85th percentile speed, percentage distanced travelled above the speed limit, and safety benefit estimation. Results indicated the use of the ISA application led to significant improvement in speed limit compliance particularly in the 60 km/h and 80 km/h zones where speeding was eliminated. There were no observed negative effects on driver speeding behaviour from the use of the system. In general, the findings suggest the use of the ISA system, resulted in the adoption of vehicle speeds that are likely to improve road safety.     

Drivers' perceptions regarding speeding and driving on urban residential streets with a 30 km/h speed limit

Previous studies have shown very little information regarding drivers' opinions, attitudes and behaviours with respect to speeding and driving on urban residential streets with a 30 km/h speed limit. The present research aims to address this issue by conducting a questionnaire study with a sample of 367 Japanese drivers. The results showed that drivers tended to have positive beliefs about complying with the 30 km/h speed limit and understand the negative consequences of speeding; however, a majority of the drivers considered breaking the speed limit as a way to reduce their travel time. While the extent of speeding was found to be very serious, a number of drivers still supported the use of a 30 km/h speed limit on residential streets and favoured protecting the right of vulnerable street users. The logistic regression models developed in this study identified that the drivers who did not support the 30 km/h speed limit were associated with those who had committed traffic-law violations, who had negative beliefs about complying with the speed limit, who did not consider residents' opinions, who believed it is acceptable for them to drive at a high speed, and who felt it difficult to refrain from speeding. With regard to anti-speeding countermeasures, under drivers' point of view, streets should be designed to make the 30 km/h speed limit more credible, although this study also showed evidence supporting the application of public awareness programmes and social campaigns as speeding interventions. In addition, this research investigated drivers' speed choices in various specific driving circumstances, and six underlying factors affecting drivers' speed choices were determined. On the basic of the findings, the implications and suggestions for speeding interventions were also discussed.     

基于贝叶斯组合模型的短期交通量预测研究

提出一种新的贝叶斯组合神经网络模型并将其应用于短期交通流量的预测。模型通过实时跟踪模型的预测表现,根据研究提出的分配算法不断调整模型的信用值,从而挑选并组合得到精度更高的预测模型。介绍了该模型的基本原理及在示范路网中的实际应用,通过选取反向传播神经网络和径向基函数神经网络,用以构造贝叶斯组合模型,并在测试数据集中进行了性能比较。计算结果表明：模型的预测性能整体上优于单一的神经网络模型,并且确保了模型预测的稳定性。     

牧区道路路基实施技术研究

通过交通部西部交通建设研究项目《牧区道路技术标准及路基路面典型结构的研究》,从对路基的一般要求——路基取弃土、路基排水、路基防护及路基压实、路基压实机具等方面论述了牧区道路路基实施技术及要求。     

考虑公路施工影响的出行OD修正方法研究

针对高速公路建设项目施工期对地方交通的干扰问题,提出了考虑公路施工影响的出行OD修正方法,从而为施工期区域交通组织方案制定提供基础数据。首先,探讨了OD矩阵的拆分方法,即由基于县市级的OD矩阵转化为基于乡镇级的OD矩阵的实现方法。然后,借鉴效用理论提出了弹性出行发生概率计算公式,用以修正弹性出行生成量,从而定量描述公路施工对地方交通出行的影响。其次,将施工运输车辆对周边路网产生的交通负荷以附加出行方式进行量化,并给出了相应的计算方法。最后,结合实际工程项目进行了案例分析,证明了上述方法的实际可操作性。     

Effect of obstacles on roads with different waviness values on the vehicle response

The effect of the increasing number of cosine-form obstacles, which are superposed on a standard homogeneous longitudinal road profile, is studied when the waviness of the basic road profile changes in the range from 1.5 to 3.5. First, the effect of the composed profile on the power spectral density (PSD) is analysed. It appears that the primary PSD in the form of a straight-line in the log-log plot breaks into two straight-line partial segments with quite different waviness values in the long and short wavelength bands. This seems to be a suitable model of a highly deteriorated road. Next, the effect on the response of two typical vehicles, viz. a personal car and a three-axle truck, is studied, and rather different results were obtained. In a summary valuation, it appears that the presence of additional obstacles causes independence of some of the vehicle response quantities of the primary waviness.     

高速公路拓宽工程硬路肩下土体注浆加固试验研究

针对杭甬高速公路拓宽工程中,原硬路肩下局部土体需进行加固以达到底基层的设计要求的问题,首次提出了采用注浆法对硬路肩下土体进行加固,并对注浆工艺和加固效果进行了试验研究,具体内容包括:注浆孔布置、注浆材料、注浆方式、注浆控制参数、施工工艺及加固效果检测等。测试结果表明:采用注浆法加固后,硬路肩下土体弯沉值减小,回弹模量和剪切波速显著增大。注浆后土体回弹模量达到设计要求,施工过程基本不影响车辆通行,且与开挖翻造法相比可节约28%的工程造价。