城市交通拥挤事件的模糊C均值聚类识别方法研究

交通拥挤事件是城市公共交通系统中造成交通延误的最主要原因之一,快速有效的识别拥挤事件是城市交通控制策略的重要环节。针对交通流相态及其交通因素类属方面存在的模糊性,本文在分析交通流特征时对其进行了聚类软化分。根据交通流特性,运用模糊C均值聚类算法对交通流各要素进行模糊分析处理。通过对交通量隶属度的判别和聚类分析结果,找出不同交通流间的亲疏程度和相似性,将具有相近特性的交通流归纳在一类,从而判别出交通流相态属性,确定交通拥挤事件的发生,达到对交通拥挤事件识别的目的。     

谈山区农村公路交通工程设计

文章分析交通工程是保障公路的准确、安全、快速、舒适,对于整个交通工程系统的合理运营起着决定性的作用。本文主要介绍进行交通工程设计的情况,分析山区农村交通工程设计中的重点问题,并提出了较为合理可行的设计和施工建议。     

基于混沌理论和PSO神经网络的短时交通流预测

交通流预测已成为智能交通的重要组成部分,针对短时交通流的非线性和不确定性,文中根据实际交通流中存在的混沌,利用C-C方法和小数据量法对交通流混沌进行了分析,在交通流混沌时间序列相空间重构的基础上构建了基于粒子群优化神经网络的单点单步预测模型,运用该模型对实际采集的美国加州城市快速路交通流数据进行了仿真研究,结果表明,该预测模型具有较高的预测精度,能够满足智能交通控制和诱导的需求。     

智能交通中单车辆最优动态路径规划策略研究

目前的交通现状,使人们无时无刻不在感受着交通拥挤、事故频发、尾气过度排放、能源供给失衡等问题,这些问题已经成为经济可持续发展中不可回避的障碍。智能交通方案是解决交通问题的一场信息化革命,动态最优路径规划策略作为智能交通出行者信息管理系统的重要问题,非常有必要值得研究。本文首先建立单车辆动态数学模型,采用基于周期的自主车辆规划算法,有效的避免拥挤的交通路段,使车辆出行代价降低,提高了车辆路径规划的实时效果和准确度。     

基于模糊层次分析法的煤炭运输网络多目标优化权重分析研究

煤炭运输网络优化设计的目标是使煤炭运输网络广义费用最小。研究的广义费用由运输费用、延误费用及其权重构成,通过分析煤炭运输网络流量分配目标,运用基于三角模糊数的模糊层次分析法得到各目标权重,进而确定各目标对总目标的贡献大小。     

基于多智能体的公交线网动态优化系统阐述

随着我国城市化建设不断加快,道路交通拥堵问题也日益严重。为解决城市交通问题,国家加大了城市公共交通发展力度。城市公交的快速发展虽在一定程度上缓解了交通压力,但也带来了多线路公交车运行区间重叠等问题。多线路公交车运行区间重叠易造成交通资源的浪费,也会使车辆碰撞等安全事故的发生几率上升。因此,在加大力度发展城市公共交通的同时,还需要寻求科学合理的公交线路调度方法,通过对相关技术手段与科技产品的运用提高公交车到站的准点率,有效降低重叠运行区间车辆串车率,为市民的出行提供方便。论文基于相关的理论、技术与经验提出一种基于多智能体的公交线网动态优化系统,对系统的原理、构成、功能等进行分析论述,以供参考。     

高速公路关键结构物安全监测的设计与实施

高速公路工程是我国新时期交通运输网的重要构成,为缓解国内日趋增大的交通压力发挥了积极作用。由于地面道路交通可供开发的区域逐渐减少,交通道路建设开始转向桥梁工程,于是安全监测成为现在高速公路安全运营的重要环节。在运营期间,安全监测不仅要规划好具体的作业流程,还要更好地实施对工程综合性的变形监测,以避免不确定因素对桥梁造成损坏从而影响高速公路的安全稳定。鉴于此,文章以虎门大桥关键结构物监测为例,探讨了高速公路结构物监测的有关事项。     

Travel time and transportation policy

This paper examines the relationship between traffic congestion and travel time. A model is developed where both travel time and the number of peak-hour trips are simultaneously determined. The model is estimated by two-stage least squares using traffic data from the Boston metropolitan area. The estimates are used to generate implications for transportation policy. The paper suggests that commuters are substantially more responsive to changes in travel time than to changes in price.     

高速公路安全管理浅析

随着我国交通建设水平的不断提高,我国高速公路建设也取得了很大的成绩。高速公路作为一种安全、高效、通过能力强的新型交通手段,极大地改善了我国的交通运输条件,缓解了以往交通拥堵的情况,不仅带动了运输效益和服务水平的提升,还有效地推动了国民经济的发展。但与此同时,在高速公路交通中,高速公路安全问题也日益凸显出来。本文就高速公路安全管理提出了一些看法,并提出了相应的解决对策。     

A mixed behaviour equilibrium model with mode choice and its application to the endogenous demand of automated vehicles

This study develops a mixed behavioural equilibrium model with explicit consideration of mode choice (MBE-MC) in a transportation system where fully automated vehicles (AV) coexist with conventional human-driven vehicles (HV). For the mode choice, travellers select among three options, following a logit modal split: driving their private HV, or taking an AV mobility service provided by either a firm or the government. For the route choice, the HV drivers follow the random utility maximisation principle while central agents route the AV passengers following the Cournot Nash (firm agent) or Social Optimal (government agent) principles. We consider two types of travel costs (i.e. travel time and monetary travel cost) to characterise the new features (e.g. expanded link capacity and reduced value of time) of the mixed AV–HV transportation system. We model the MBE-MC problem in a combined mode–route choice framework and formulate it as a route-based variational inequality (VI) problem. We show the equivalence between the VI formulation and the MBE-MC problem, and the existence of a solution to the MBE-MC problem. Then, we modify a partial linearisation algorithm for solving the proposed model. Numerical results validate the equilibrium conditions and show the efficacy of the new model in capturing the features of the mixed AV–HV transportation system. The impact patterns of different parameters on (1) the network performance in terms of AV share and system cost and (2) on the solution efficiency are analysed.     

基于预知OD的城市路网交通流路径优化研究

针对城市路网交通流分布不均引起的交通拥堵问题,提出了在预约出行交通背景下基于预知OD的交通流路径优化方法。首先,分析了预约出行交通背景下预知OD的数据环境;其次,根据动态用户均衡准则,对预知的OD进行流量分配,给出预约出行车辆的路径;接着,使用预测控制的方法,结合路网上预约车辆的状态,以路网上路段的饱和度和未预约车辆的行程时间最小化为目标,从系统和用户两个角度对未预约车辆的路径进行实时的诱导,通过连续时域的滚动优化控制,优化交通流的路径;最后,对本方法的实现和应用做了思考和探索,对本研究做了总结。     

西安市老城区交通问题分析及改善策略

改善与优化老城区的交通是城市交通发展的一个重要课题。文章通过分析西安市老城区交通问题,以减少老城区内交通量和优化出行环境目的,提出了改善老城区交通及优化老城区空间环境的几点对策,希望对整合西安市道路资源、缓解和改善老城区交通压力有一定参考意义。     

Insights into the effect of traffic congestion on distribution network characteristics – a numerical analysis based on navigation service data

This research studies effects that the average increase in travel times due to road traffic congestion has on characteristics of an existing distribution network. It presents the most detailed estimate of ‘on-the-road’ effects on distribution network characteristics up to now, from the network modelling perspective and from the processed data point of view. A concrete network model allowing for the representation of all relevant transportation flows is presented. The processed traffic information relies on navigation service data. The use of such data allows the requirements that arise for the traffic analysis of a whole distribution network to be met. It is shown that this data source may considerably contribute in forthcoming research. The effects of traffic congestion are quantified to get insights into the extent to which regular traffic congestion affects distribution network characteristics and to understand the mitigating effect when the number of distribution centres is increased.     

Peak-Load Pricing of a Bottleneck with Traffic Jam

This paper generalizes the model of bottleneck congestion such that formation and development of traffic jams is explicitly formulated. The model is applied to the peak-load problem for the morning rush hour: every morning, a fixed number of commuters travel across a roadway, and each of them chooses departure time to minimize commuting cost consisting of travel time cost, scheduling cost, and toll. Equilibrium and optimal patterns of departure are solved and optimal peak-load toll is derived. Incorporating traffic jams alters the earlier results in the literature. That is, road users may be better off from paying the optimal peak-load toll. Conditions under which such a result is obtained are identified by simulations.     

Multivariate time series analysis of traffic congestion measures in urban areas as they relate to socioeconomic indicators

Traffic congestion has significant adverse implications for the environment and economy. Many state and local transportation agencies have implemented traffic congestion management practices to alleviate the negative implications of urban traffic. One of the major drawbacks of traffic congestion management practices is that they do not account for socio-demographic and economic factors, which have a significant impact on traffic congestion. Understanding the influence of these factors is very crucial because they can help to communicate the system's performance management and target setting. Only a few studies analyzed the relationship between traffic conditions (e.g., traffic demand and vehicular traveling speed) with a limited number of socio-economic factors. Moreover, most of the existing models ignore the temporal and spatial autocorrelations of traffic congestion, which may significantly limit their reliability and effectiveness. This study is developed with the purpose of identifying the most relevant external factors that affect traffic congestion performance measures. To conduct the research, we have used three urban congestion performance measures collected from 51 metropolitan areas across the U.S. over a four-year period, 2013–2016: travel time index, planning time index, and congested hours. We have used multivariate time series models to account for the complex inter-relationships among the performance measures and socioeconomic factors to identify the most influential factors affecting system performance. We have finally developed predictive models to estimate the traffic congestion measures using these factors. The results of rigorous modeling show that the factors influencing the traffic congestion measures are monthly average daily traffic (MADT), the number of employed, rental vacancy rate, building permits, fuel price index, and Economic Conditions Index (ECI). The prediction models indicated that the effects of these factors are statistically significant and could be used to forecast future trends in three performance measures accurately.     

基于改进蚁群算法的物流配送路径研究

车辆路径问题（Vehicle Routing Problem,VRP）是近几十年来运筹学、应用数学、网络分析、图论、计算机应用及交通运输等学科研究的一个热点问题,其产生于现实的公路交通运输领域,并在通讯、生产、国防、生物、计算机应用等领域得到了广泛的应用。本文着重研究有时间窗的车辆路径问题（Vehicle Routing Problem with Time Windows,VRPTW）}VRPTW现已被证明为NP-hard问题,当问题规模较大时,将很难得到问题的精确解。探讨如何经过少量的计算,得到一个相对满意的解,已成为现阶段学者研究的重点。文中提出用混合蚁群算法求解VRPTW,有效的缓解了信息传递快速与物流反应缓慢的矛盾,提高了物流配送的科学化效率,对电子商务物流配送的发展具有一定的理论意义与应用价值。     

我国城市交通现状及对策分析

城市交通系统是一个城市高速运转和保持活力最主要的基础设施之一。近年来,随着城市人口和私家车的快速增长,城市交通问题越来越突出,已经成为许多城市所面临的难题之一。基于我国城市交通现状及存在的问题,主要采用定性分析的方法提出了促进城市交通系统健康可持续发展的对策措施,进而达到优化城市交通结构、改善居民出行环境的目的。     

基于Intranet的交通信息管理系统

在分析交通信息管理系统功能的基础上，利用网络技术建立办公自动化、运输管理自动化信息系统。进行系统安全分析、研究系统实施措施与手段。     

对管道施工中管材运输的安全保障措施的研究

管材运输是管道施工的必要环节和关键步骤,没有完整、安全、高效的管材运输,就无法保证管道施工的质量、安全和效益。目前,管道施工过程中对管材运输的安全保障意识不强,存在划破管材、磕碰岩体、沾泥带水等影响管材质量的情形,也存在解挂失误、操作不当等造成人身伤亡的问题,因此,为了保障管材运输的安全和效率,本文就管道施工中管材运输的安全保障措施进行研究,以期对管道施工方法的改进有所裨益。     

《交通工程学》课程的建设与思考

交通工程学是交通工程、交通运输、安全工程等专业的主要专业基础课。该课程涉及的交通流的基本特性、交通调查的一般方法、交通流理论、通行能力、交通管理与控制等知识内容,对培养学生解决专业问题的能力是必不可少的。石家庄铁道大学具有交通运输工程一级学科硕士学位授予权,一直将《交通工程学》做为重要课程讲授,本文简要介绍该课程的建设和相关思考。