基于视频的行人检测算法研究

文章提出了一种基于视频图像的行人检测算法。通过动态阈值目标分割算法获得运动目标,同时将分割结果块化处理,以减少算法时间复杂度。使用最小外接矩形获得目标的高宽比,结合基于质心的目标跟踪方法获得目标物体运动速度,进而对行人事件进行检测。实验结果表明,该方法能准确地检测交通场景中的行人事件,有效地解决抖动、光线及积水等因素对行人目标检测的影响,具有良好的实时性和准确性。     

交通监控与指挥管理系统的设计及系统测试分析

在智慧城市建设背景下,将大数据、互联网等信息技术应用到交通管理领域,打造交通监控与指挥管理系统,对解决交通拥堵问题、提升道路通行效率有积极帮助。首先介绍交通监控与指挥管理系统的层次结构,包括展示层、部署层、业务逻辑层等。随后对该系统的道路信息管理、视频监控管理、交通车辆定位指挥等功能模块的设计要点展开分析。最后对交通监控与指挥管理系统的车辆定位监控功能展开测试。结果表明该系统可以通过车辆定位监控实时获取车道的车流量情况,并自动生成流量统计图表,在指导市民错峰出行和缓解道路拥堵情况等方面发挥了重要价值。     

基于问题的交通产业政策规划方法

从“问题”出发,研究中国交通产业,进而提出目标合理操作性强的“产业政策”,是进行交通产业政策研究的有效途径;同时,由于产业政策规划中方案合法化和执行评估的需要,该研究又必须是在充分考虑相关权力组织背景下的产物。结合实践,提出了中国交通产业结构调整产业政策规划的思路。     

基于计算机视觉技术的交通场景检测平台的设计与应用

文章针对当前城市智慧交通监管的路口交通的饱和度、拥堵以及闯红灯等问题,设计了基于计算机视觉技术的交通场景检测平台,结合机器学习算法,并融合多项高新技术,实现对路口过往车辆的流量和车速检测,对机动车闯红灯、斑马线不礼让行人、占用公交车道、违停或违规越线等违章行为进行检测识别,为公共交通的管理提供极大便利,实现了“智慧交通”和“平安交通”。     

Vistro在交叉口信号优化中的应用研究

Vistro在交通设计和规划方面优势突出,文章主要阐述Vistro在交通信号配时优化方面的应用,介绍了其优化原理与步骤,并以唐山市北新道与建设路交叉口为研究对象,在现有交叉口的属性数据和信号配时数据的基础上,使用Vistro软件进行路网的构建并设置相应参数和控制类型,通过后台的优化处理给出优化结果。通过与Webster配时算法生成方案进行比较,验证Vistro在交叉口信号优化中具有很好的实用性和高效性。     

城市交通安全文化建设初探

<正>一、城市交通安全文化建设的背景分析1.城市交通安全文化建设的必要性随着我国城市化建设步伐的不断加快,我国的城市交通情况越来越不容乐观。如何有效疏导交通,降低交通事故率是城市居民最为关心的问题之一。通过对城市交通事故的原因分析,可发现约80%～85%的交通事故是由于交通违法行为造成的。在制度不可谓不全、管理不可谓不严、惩罚不可谓不重的情况下,为什么交通违法行为还是频繁发生?归根结底还是交通参与者的安全理念不强,安全意识淡薄,安全素质低下,没有严格遵守道路安全的规章制度,导致了他们在交通安全行为上的偏差。     

网联环境下混合交通分配模型

为了提高混合交通环境的路网通行效率，对存在城市CAV专用区域的情况下的混合交通分配进行了研究。本文在混合交通环境的背景下，考虑混合交通具有不同的路由准则，因此构建了相应的混合交通分配模型，通过设置CAV专用区域提升系统通行效率和CAV车辆使用率，采用SRA算法求解。最后进行了算例分析，通过结果可以看出，设置CAV专用区域可以将系统通行效率提升26%，当CAV车辆系统服从率为1，相比于系统服从率为0.8时，系统通行效率提升6%。     

基于分布式计算机的智能相机在城市交通中的研究与应用

我国逐步开始将城市建设与互联网技术进行高度融合以打造智能城市。智能城市建设过程中,智能交通是重要一环,当前我国交通视频监控系统普遍是通过道路两旁的摄像头拍摄获得路况图像信息,这种方式虽然是解决了一些问题,但是不能满足智能城市的建设需求。本文总结和研究了分布式智能相机的一些关键技术,得出嵌入式设备高效率、低耗能的优点使其在交通监控领域得到了越来越广泛的应用,基于分布式计算机设计了智能相机的分布式智能城市交通系统,提出了一系列有益于提升系统运行的具有应用前景的算法,用来解决使用重叠视野进行跟踪和稀疏相机网络中的有效跟踪。     

基于时间序列的航路随机交通流复杂度研究

本文参照数学算法复杂度模型并对其作出改进,建立了基于时间序列的航路交通流复杂度模型,给出了算法复杂度和近似熵复杂度两种模型的算法步骤,在短时和长时两个方面,从管制员的角度分析实时交通流并掌握交通流的复杂度,从而为发出正确的管制指令、合理安排航路流量提供参考。通过运用Matlab模拟经过某航路的航空器速度,仿真生成了两种不同状况下复杂度变化的情况。结果表明,该模型对缓解交通拥挤,分析交通流复杂度具有一定的现实意义。     

高速公路场景下的电子稳像技术研究

为了去除高速公路监控视频中自身位置不稳定的事物给全局运动矢量估计带来误差,先通过Canny算子检测图像中的直线,并根据车道边界的特征筛选出道路边界,确定道路区域。再检测道路区域内的Harris角点信息,并与背景图中道路区域内的角点位置进行匹配,从而得到全局运动矢量,并计算出稳定的图像。实验表明,该算法能够满足高速公路场景下的稳像需求。     

基于DSP的先进视频交通数据采集系统探讨

DSP是一种先进的视频交通数据采集系统,它操作简单,不仅能够有效的融入于道路交通数据采集系统,还能够与感应式十字路口信号灯控制系统、电子警察抓拍系统相结合,其双重功用被广泛应用于城市道路、高速公路交通数据采集,以及公路隧道、桥梁的意外事故监控系统中,并且可以适应各种天气,具有全天候检测的能力。文章从系统特点、检测数据精度、系统的多功能性及系统操作的方便性等方面介绍了该系统的先进性、实用性。     

Bayesian updating of trip generation data: Combining national trip generation rates with local data

With traffic impact analyses and impact fee assessment becoming more popular, the need for accurately estimating the trip generation rate of a proposed development is becoming more important. An overwhelming percentage of state transportation agencies depend either partly or entirely on the ITETrip Generation Report to predict the traffic that will be attracted to and/or produced from a proposed development. However, the rates obtained from the ITE publication have been derived from data collected throughout the United States. They represent a national average and fail to take into account the local trip generation characteristics that the site under consideration might have. This paper establishes a methodology for obtaining more reliable local trip generation rates using Bayesian statistics. In this method, the ITE rates are assumed to be the prior information, which are updated using limited local trip generation data that are available. The method also allows for temporal updating, incorporating subjective judgment and using borrowed data in the updating procedure. Sample calculations in this paper illustrate the developed methodology.     

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.     

基于贝叶斯网络模型的交通状态预测

城市的交通状态是可以预测的。有效的交通状态预测能优化交通状态,减少交通阻塞。贝叶斯网络(Bayesian Networks,BN)是目前不确定知识和推理领域最有效的理论模型之一。文章在综合考虑交通阻塞成因的基础上构建网络模型,在已有的交通状态数据的基础上提出基于贝叶斯法则的学习算法,并通过计算变量间的条件概率来计算交通阻塞发生的可能性,达到预测的目的。     

地铁站点施工期交通组织工作思路与方法

由于地铁站点施工对城市交通会产生极大的影响,因此提前做好施工期间系统的交通组织工作,对保障城市正常生产、生活和地铁站点的顺利施工有着重要意义。文章结合成都地铁二号线站点施工期间交通组织工作经验,针对地铁施工的特点,就施工期间的交通组织工作思路、方法等进行探讨。     

国道106线阳河中桥的加固方法

随着交通量日益增长,部分旧石拱公路桥梁已不适应目前交通的需要,文章以国道106线阳河中桥为例,介绍利用套拱的加固方法,解决了旧石拱桥的承载能力,减小了对旧桥桥面的破坏,延长了桥梁的使用寿命。     

Recursive estimation of average vehicle time headway using single inductive loop detector data

Vehicle time headway is an important traffic parameter. It affects roadway safety, capacity, and level of service. Single inductive loop detectors are widely deployed in road networks, supplying a wealth of information on the current status of traffic flow. In this paper, we perform Bayesian analysis to online estimate average vehicle time headway using the data collected from a single inductive loop detector. We consider three different scenarios, i.e. light, congested, and disturbed traffic conditions, and have developed a set of unified recursive estimation equations that can be applied to all three scenarios. The computational overhead of updating the estimate is kept to a minimum. The developed recursive method provides an efficient way for the online monitoring of roadway safety and level of service. The method is illustrated using a simulation study and real traffic data.     

Using geometric primitives to calibrate traffic scenes

In this paper, we address the problem of recovering the intrinsic and extrinsic parameters of a camera or a group of cameras in a setting overlooking a traffic scene. Unlike many other settings, conventional camera calibration techniques are not applicable in this case. We present a method that uses certain geometric primitives commonly found in traffic scenes, such as straight and curved lanes, lane markings, and poles in order to recover calibration parameters. We show experimentally that these primitives provide the needed redundancy and are capable of achieving accurate results suitable for most traffic monitoring applications.     

Understanding the structure of hyper-congested traffic from empirical and experimental evidences

We study in this paper the structure of traffic under hypercongestion, which is a controversial issue between traditional two-phase traffic theory and Kerner’s three-phase theory. By analyzing video traffic data from a section of the Nanjing Airport Highway, it is found that traffic states inside hypercongestion are not homogeneous, which contradicts the existence of a “Homogeneous Congested Traffic” state claimed in two-phase traffic theory. Analysis of vehicle trajectories and velocities obtained from an experimental car-following study with a platoon of 25 vehicles also confirms the above findings. Furthermore, it is also found from the video traffic data that the structure of hypercongested traffic varies only slightly with location, which might be due to small jams inside hypercongested traffic merging into larger ones slowly and/or larger jams sometimes breaking into small ones. Finally, the implications of our observations on traffic modeling have been discussed.