Information routière par RDS-TMC: enjeux de l'interopérabilité

There was a range of systems and technologies for broadcasting road traffic information in different countries in the European Union and interoperability between the various systems must be achieved to enable road users to use the same on board equipment in different countries so that they can receive the same information service in their own language throughout a journey, whether local, regional, national or international. This paper mainly deals with the broadcasting of road, traffic information via RDS-TME and begins by describing some technical features of this medium. If the proceeds to examine issues of interoperability between RDS, TME based road traffic information systems.     

公路列车的体系框架与关键技术

环保、安全是交通运输领域备受关注的两大重要问题,智能交通系统(ITS)是解决这两大问题的一种有效方法。公路列车(Road Train)系统作为车用自组织网络(VANETs)在ITS领域的一个特殊应用,通过车车协同,整个公路列车队中,除头车由驾驶员驾驶,其他车辆都受头车发送的控制数据控制其自动驾驶。该系统集成了微电子技术、网络通信技术、多传感器集成技术以及车辆自动控制技术,旨在提高交通运输的安全性以及减少其所带来的环境污染,同时增加驾驶舒适性,其核心思想是通过车车通信的方式实现车辆之间的列队协同列队行驶。首先介绍了公路列车系统的概念,分析了公路列车系统的优点,提出了公路列车系统的体系框架结构,深入讨论了公路列车系统中所包含的关键技术,最后对公路列车系统进行了总结。     

虚拟交控中心建置与应用

在交通问题日益繁杂的情况下,交控策略往往为改善交通问题的重要手段,而策略的拟定必须透过广泛且正确的各项资料作为基础,虚拟交控中心（virtualtrafficcontrolcenter,VTC）的建置便占重要的角色。一方面为实际交管中心（trafficmanagementcenter,TMC）资料做备份,一方面可将资料提供与学术单位进行交控策略的拟定,并且亦可透过与实际交管中心相同使用者介面进行教育训练,进一步培养交控人才。文中完成虚拟交控中心的系统建置,并开发交控策略绩效平台,将虚拟交控中心模拟软体所得到之时制计画及其绩效,透过资料库同步方式将交控策略回颌台中市政府交管中心。虚拟交控中心未来将持续蒐集车流资讯,开发软体,期望达到改善都市交通问题之目标。     

区域ITS项目实施的综合排序方法研究

区域ITS项目实施的综合排序主要受到ITS项目实施的需求程度、影响程度、实施效益以及需要实施的ITS项目之间的内在关系的制约。采用DEMATEL方法对ITS项目实施的需求程度进行排序，采用层次分析法对ITS项目实施的影响程度和实施效益分别进行排序，并提出了采用线性综合排序方法对ITS项目的实施进行综合排序，最后分析ITS系统实施的内在发展规律以此对ITS系统实施的综合排序进行调整。此排序方法即考虑了项目实施的外在因素，又兼顾了项目的内在发展关系。同时将该方法用于江苏省公路ITS项目的实施排序中，避免了ITS项目实施的主观臆断性。     

A perspective on ITS deployment

The intelligent transport systems (ITS) deployment begins with implementation of traffic control signals and traffic management on a road network. The next stage is the provision of traffic information to drivers. The third stage is the decision and operation assistance to drivers for safe driving. It will take time to reach the final stage of a fully automated driving because of the difficulties of getting social acceptance. Another final figure of ITS is that all transportation modes are integrated and provide continuous transportation service to users from door to door. Mobile information terminals such as cellular phones and motor vehicles will function as well as ordinary offices and homes. Then the ITS as an information system will be integrated into a general social information system.     

Effective traffic routing for urban transportation capacity and safety enhancement

Traffic routing is an essential service in most intelligent transportation systems (ITS), especially in urban traffic networks of large cities. However, this is a challenge issue as these traffic networks are complicated and traffic conditions change dynamically. Existing routing solutions from technology giants such as Google Maps, Waze are still insufficient in terms of accuracy (effectiveness) and efficiency (performance), especially applying in developing countries where traffic infrastructures have not yet matured enough, leading to degradation of transportation performance, safety while increasing traffic jam, economic loss, air and noise pollution. This work proposes an effective routing approach in large cities to avoid traffic congestion, enhancing transportation capacity and safety. Concretely, this work designed an appropriate urban traffic data organization scheme and devised a novel approach to searching solutions in an optimal routing algorithm, thus improve the routing performance significantly. Results from real-field experiments confirm the effectiveness and the efficiency of the proposed approaches which are prominent compared to the state-of-the-art solutions. The proposed approaches have been applied in a real urban traffic network of Ho Chi Minh City, the biggest city in Vietnam whose traffic is complicated. The experimental results and the practical deployed system reveal that the proposed mechanisms are ready to be applied in real-world applications.     

基于ETC技术的高速公路综合信息平台应用设计

智能交通系统(ITS)是交通运输系统的重要发展方向,而电子不停车收费系统(ETC)作为ITS的重要组成部分,正在国内大力推广应用。基于我国高速公路信息管理及ETC系统应用与发展的需求,提出了基于ETC技术的高速公路综合信息平台的设计方案,讨论了建设该平台所面临的若干关键技术,并对其发展与应用趋势作了总结。     

北京市交通信号管理与控制平台设计及应用

在分析现有交通信号系统的特性以及存在问题的基础上,以对现有信号系统进行有效整合、综合利用交通流数据、提高交通信号控制的管理水平为目标,设计了1种集成的交通信号控制平台,并给出了平台在北京市交通信号管理与控制系统中的应用。     

Data Fusion-Based Traffic Density Estimation and Prediction

Traffic congestion has become a major challenge in recent years in many countries of the world. One way to alleviate congestion is to manage the traffic efficiently by applying intelligent transportation systems (ITS). One set of ITS technologies helps in diverting vehicles from congested parts of the network to alternate routes having less congestion. Congestion is often measured by traffic density, which is the number of vehicles per unit stretch of the roadway. Density, being a spatial characteristic, is difficult to measure in the field. Also, the general approach of estimating density from location-based measures may not capture the spatial variation in density. To capture the spatial variation better, density can be estimated using both location-based and spatial data sources using a data fusion approach. The present study uses a Kalman filter to fuse spatial and location-based data for the estimation of traffic density. Subsequently, the estimated data are utilized for predicting density to future time intervals using a time-series regression model. The models were estimated and validated using both field and simulated data. Both estimation and prediction models performed well, despite the challenges arising from heterogeneous traffic flow conditions prevalent in India.     

智能汽车横纵向运动控制方法综述

在我国随着人民生活水平的提高,车辆保有量也在呈倍速增长,进而引起了大量的交通安全问题,其中由驾驶员操作不当引起的交通事故约占所有交通事故的75%。而汽车的智能化发展可以很好地解决此类交通安全问题。智能汽车的核心技术主要包括环境感知、行为决策及运动控制三方面。其中运动控制作为智能汽车核心技术之一,有着重要的研究意义。智能汽车的运动控制包括横向控制和纵向控制两部分,对汽车横、纵向运动控制中的多种方法进行了分析介绍,包括模型预测控制、模糊逻辑控制、神经网络的自适应滑膜控制、直接式控制和分层式控制;同时介绍了横纵向耦合实现运动控制的重要性,并分析了其研究现状;最后,对智能汽车运动控制的后续发展方向进行了展望,有助于智能汽车运动控制的进一步优化发展。     

Design and simuation of a vehicle test bed based on intelligent transport systems

As growing demand of vehicle safety system, especially regarding intelligent transport systems (ITS), automotive manufacturers are focusing more on driving safety and efficient transportation for vehicle users. Many safety systems have been launched in the market recently so, it is important to evaluate the vehicle safety systems and ITS. The ITS based intelligent vehicle test bed was constructed to meet the growing demand of test and verification for such ADAS and ITS systems. First, this paper describes in detail concept of the test-bed. This test-bed is carefully designed to meet the requirements of ISO/TC204 standards. In order to verify the design of the test-bed, virtual test with driving siulator was processed on a virtual test tracks. This test-bed will be used to conduct testing on various ITS and ADAS technologies, such as adaptive cruise control (ACC), lane departure warning system (LDWS), cooperative intersection warning system as well as rollover stability control (RSC) and electronic stability control (ESC), etc.     

A Comparative Study of Three Multivariate Short-Term Freeway Traffic Flow Forecasting Methods With Missing Data

Short-term traffic flow forecasting is a critical function in advanced traffic management systems (ATMS) and advanced traveler information systems (ATIS). Accurate forecasting results are useful to indicate future traffic conditions and assist traffic managers in seeking solutions to congestion problems on urban freeways and surface streets. There is new research interest in short-term traffic flow forecasting due to recent developments in intelligent transportation systems (ITS) technologies. Previous research involves technologies in multiple areas, and a significant number of forecasting methods exist in the literature. However, most studies used univariate forecasting methods, and they have limited forecasting abilities when part of the data is missing or erroneous. While the historical average (HA) method is often applied to deal with this issue, the forecasting accuracy cannot be guaranteed. This article makes use of the spatial relationship of traffic flow at nearby locations and builds up two multivariate forecasting approaches: the vector autoregression (VAR) and the general regression neural network (GRNN) based forecasting models. Traffic data collected from U.S. Highway 290 in Houston, TX, were used to test the model performance. Comparison of performances of the three models (HA, VAR, and GRNN) in different missing ratios and forecasting time intervals indicates that the accuracy of the VAR model is more sensitive to the missing ratio, while on average the GRNN model gives more robust and accurate forecasting with missing data, particularly when the missing data ratio is high.     

轨道交通建设对既有交通影响及解决措施

随着多条线路引入社会资本参与建设，天津市轨道交通建设已经进入全面加速时期。目前，在建的几条线路均为穿越城市中心区的放射线路，沿线途经城市交通干道引起道路路段以及路口的通行能力降低。因此有必要深入研究地铁施工给城市道路交通带来影响的具体表现，分析不同施工工法，不同疏解方式对机动车、非机动车、行人、周边环境的影响, 结合现场调查和仿真模拟，科学评价交通组织方案，及时发现不足并有根据地进行交通组织优化，更好的解决地铁施工所带来的城市道路交通问题。     

动态交通信息处理技术研究

信息是智能交通系统的关键,ITS的各种功能都是以信息应用为中心展开的。交通信息处理系统是ITS各子系统联系的纽带和中枢,为ITS提供信息保障。阐述了交通信息处理系统的重要性和基本功能,对国内外交通信息处理技术进行了分析比较。在此基础上给出了系统框架流程设计,并对交通数据质量控制、信息融合、交通数据集成和存储等信息处理的关键技术进行了探讨。     

基于ITS技术的汽车驾驶安全辅助系统

基于ITS技术的汽车驾驶安全辅助系统是提高道路交通安全的有效手段,本文介绍了清华大学汽车安全与节能国家重点实验室在此领域的研究与开发工作。在研究行驶环境感知和信息融合、驾驶员特性和安全距离模型、车辆运动控制及系统集成等关键技术的基础上,研制了汽车驾驶安全辅助系统试验平台和试验样车,实现了行车前撞预警、安全车距保持、智能车道保持等功能,并完成了相关试验分析与评价,为进一步开展基于ITS的汽车主动安全辅助技术的研究以及汽车驾驶辅助系统的产业化奠定了基础。     

ITS在我国道路安全管理中的应用与对策分析

针对我国目前的道路交通安全形势,分析了在道路交通安全管理中发展智能交通的必要性.阐述了ITS技术在欧美发达国家道路交通安全管理中的研究重点与发展现状.以此作为参考,分析了智能交通系统在我国道路交通安全管理中的研究与应用现状,从而揭示了ITS在我国道路交通安全管理中存在的问题与不足,并提出了解决相关的问题的措施与建议.     

Public transportation development and traffic accident prevention in Indonesia

Traffic accidents have long been known as an iceberg for comprehending the discrepancies of traffic management and entire transportation systems. Figures detailing traffic accidents in Indonesia, as is the case in many other countries, show significantly high numbers and severity levels; these types of totals are also evident in Jakarta, the highest-populated city in the country. While the common consensus recognizes that traffic accidents are the results of three different factor types, namely, human factors, vehicle factors, and external factors (including road conditions), human factors have the strongest influence—and figures on a worldwide scale corroborate that assertion. We, however, try to pinpoint the issues of non-human factors in light of increasing traffic accidents in Indonesia, where motorbike accidents account for the majority of incidents. We then consider three important pillars of action: the development of public transportation, improvement of the road ratio, and traffic management measures.     

浅谈航运新形势下内河海事监管技术的发展

随着我国内河航运的迅猛发展,船舶交通流的密集化和复杂化程度越来越高,通航秩序日益复杂,水上交通事故时有发生,对水上安全监管提出了更高的要求。文中介绍了目前国外内河水上运输和安全监管现状,结合国外的先进管理理念,围绕安全和效率两大主题,运用先进的信息技术、管理技术和风险分析技术,研究海事监管技术的发展方向,为水上运输提供有力的安全保障。     

基于数据挖掘技术的智能交通信息分析与决策研究

智能交通系统是解决当今交通问题最有前途的手段之一,而交通信息的分析与处理是其核心问题。首先介绍智能交通系统的信息特征及其分析要求,剖析了当前国内外常用的分析方法在信息处理与辅助决策方面存在的不足,提出了一个完整的、针对智能交通行业的交通信息智能分析与辅助决策系统模型。该模型以数据挖掘技术为核心,全面运用了新一代决策支持系统理论和计算智能技术,最后阐述了模型的各主要组成部分及其关键技术与实现方案。     

接入管理技术在青岛地区的应用初探

基于接入管理技术的优势,结合青岛地区的交通现状,提出了适合青岛地区的接入管理技术。研究对于改善青岛地区的交通拥挤、提高交通安全和通行效率以及维护城市环境等具有现实意义。