大数据助力智能交通发展

基于当前大数据技术对智能交通的影响,介绍了大数据的基本特征,分析了大数据与智能交通之间的关系,以及大数据时代智能交通面临的问题和挑战,并从不同层次探讨了大数据时代智能交通未来的发展和机遇,指出依托大数据技术,挖掘交通数据资源,构建交通数据处理模型,推进智能交通发展成为改善城市交通的有效途径。     

基于改进的BP神经网络探究航空与陆侧客流关系

为提高航空与陆侧交通客流关系分析的效率,本文基于大数据手段统计海量的航空客流和陆侧交通客流数据,利用改进的BP神经网络算法对航空客流和陆侧交通客流的关系进行了研究。首先,通过遍历隐含层神经元个数并增加算法运行次数的方法探寻隐含层最佳神经元个数。其次,保持航空客流数据不变,在时间轴上偏移陆侧交通客流数据,基于拟合系数设定评价函数,衡量航空客流和陆侧交通客流数据的匹配程度。其三,基于首都国际机场的实际数据进行实例分析,得到航空旅客乘坐陆侧交通方式提前到达和滞后离开机场的时间,并获得了航空客流和陆侧交通客流之间定量关系表达式,为机场陆侧交通设施的建设和改善提供了参考依据。     

大数据视角下的智慧交通：应用实践与发展建议

当前信息技术的迅猛发展给智慧交通的发展产生了重要影响。以数据为核心的大数据技术改变了交通服务方式,打开了智慧交通发展的新思路,为智慧交通带来了新的科技内涵。本文剖析了大数据技术在智慧交通中的应用实践,分析了大数据时代下智慧交通现阶段存在问题,并对智慧交通发展提出了思路建议。     

广西交通交易大数据商业价值及变现方法研究

伴随"交通+产业"所激发的活力,广西交通交易大数据正呈现大规模聚集趋势。文章分析了广西交通交易大数据的商业价值,介绍了交通交易大数据资源配置策略,并研究了交通交易大数据商业价值变现的方法。     

大数据技术在智能交通领域的应用

在新时代背景下,以大数据理念为依据的智能化交通建设成为优化城镇化建设水平,解决城市交通拥堵的有效举措,其不仅能提升获取交通信息的科学性和准确性,而且可以构建多元化的管理系统为智能交通运行提供基础保障。文章以广西为例,基于大数据与智能交通理论概念,介绍了基于大数据技术的处理平台特点与架构,探讨了智能交通领域大数据技术的具体应用。     

基于车牌识别数据的车辆使用特征研究:以上海市快速路非沪车牌识别数据为例

随着智能交通技术的不断发展,交通信息采集系统日渐成熟,车牌自动识别系统,车牌识别数据包含了大量的牌照信息和出行时空信息。本文通过对上海市车牌识别数据,从时间维、空间维、车辆属性维、车辆使用特征维等多个维度对车牌识别数据进行挖掘,分析路网的交通构成,反映城市机动车的使用现状。该研究对于分析城市交通出行特征具有重要的参考价值,提供了新的分析技术手段,辅助决策者合理地制定交通政策,引导交通结构和交通方式的发展。     

试述大数据在智能交通领域的应用

随着经济社会的发展和人类文明的进步对交通出行的深刻影响,使得交通路况日趋复杂,智能交通是解决这一问题的重要途径之一,大数据时代的来临,为智能交通的发展及运用提供了技术性支持。通过高效、精准、及时的交通数据获取,构建合理的城市交通管理体系,以期为市民提供生活、生产便利。     

基于交通大数据的动态交通状态预测及全局路径规划研究

为提高动态交通状态预测的准确性,对基于交通大数据的动态交通状态预测及全局路径规划进行研究。以交通大数据为基础,获取指定路段的属性信息与采集信息,通过对样本数据进行描述,得到该路段的试验数据。在具体的预测和分析阶段,构建基于交通大数据的预测模型,实现对动态交通状态的可靠预测。试验结果表明,时间特征值对交通流量的影响较大,某一时间段的交通状态数据可为全局路径规划提供数据源,有利于相关人员作出科学决策,可更好地满足当前智慧交通管理新需求。     

城市交通管理系统建设若干问题探讨

文章总结了交通管理发展历经的传统交通工程规划、数字交通和智能交通三个阶段的特点,指出智能交通管理系统发展应建立在完善的数字交通基础之上。在给出数字交通管理系统的框架后,文章对交通管理系统建设中的检测器布点、数据标准化和模型技术等问题进行了探讨。     

内蒙古交通环境监测信息处理平台的构建与应用

针对内蒙古自治区公路建设里程逐年快速增长的发展态势,建立与完善交通环境监测信息处理平台,是动态掌握区域内交通环境质量状况与变化趋势的重要途径。基于内蒙古自治区交通运输环境监测网络建设试点工程,通过集成在线监测设备、地理信息技术、数据统计与分析等技术,建成了内蒙古交通环境监测信息处理平台,从而为自治区交通环境监督管理和宏观决策提供了有力的基础数据和技术支撑。     

基于MATLAB与ARM的数据通信系统

针对传统单片机与上位机的数据采集与通信系统的速度与外扩展局限性,文章构建了一种基于ARM与以MATLAB为上位机的通信系统。该系统主要运用MAT-LAB新增的设备控制工具箱实现STM32与MATLAB之间的串口通信,简化了流程,提高了工作效率。通过应用该系统对ADXL345采集的加速度信号与MATLAB进行实时通信试验,结果表明该系统通信准确、运行稳定,可用于桥梁结构的健康监测数据传递。     

Measuring energy and environmental efficiency of transportation systems in China based on a parallel DEA approach

Because of China’s rapid economic development, its transportation system has become one of China’s high-energy-consumption and high-pollution-emission sectors. However, little research has been done which pays close attention to China’s transportation system, especially in terms of energy and environmental efficiency evaluation. In this paper, data envelopment analysis (DEA) is applied to measure the energy and environment performance of transportation systems in China with the goal of sustainable development. This paper treats transportation as a parallel system consisting of subsystems for passenger transportation and freight transportation, and extends a parallel DEA approach to evaluate the efficiency of each subsystem. An efficiency decomposition procedure is proposed to obtain the highest achievable subsystem efficiency. Our empirical study on 30 of mainland China’s provincial-level regions shows that most of them have a low efficiency in their transportation system and the two parallel subsystems. There are large efficiency differences between the passenger and freight transportation subsystems. In addition, unbalanced development has occurred in the three large areas of China, with the east having the highest efficiency, followed by central China and then west. Therefore, more measures should be taken to balance and coordinate the development between the three large areas and between the two subsystems within them. Our analysis approach gives data for determining effective measures.     

Special issue on intelligent transportation systems,big data and intelligent technology

ABSTRACT

Based on the increasing demands of transportation development, the concept of an Intelligent Transportation System (ITS) has received increasing attention in both academic and industry arenas. It integrates information, communications, computers and other technologies, and applies them in the field of transportation to build an integrated system of people, roads and vehicles by utilizing advanced data communication technologies. It can establish a large, fully functioning, real-time, accurate and efficient transportation management system. Intelligent transportation systems shift the focus from road managers to road users. In order to achieve this purpose, intelligent transportation systems use advanced technology to provide drivers with convenient information to help reduce traffic congestion and to increase available road capacity. This special issue is dedicated to exploring the most recent advances in intelligent transportation systems and big data based on intelligent technology.     

Detailed assessment of global transport-energy models’ structures and projections

This paper focuses on comparing the frameworks and projections from four global transportation models with considerable technology details. We analyze and compare the modeling frameworks, underlying data, assumptions, intermediate parameters, and projections to identify the sources of divergence or consistency, as well as key knowledge gaps. We find that there are significant differences in the base-year data and key parameters for future projections, especially for developing countries. These include passenger and freight activity, mode shares, vehicle ownership rates, and energy consumption by mode, particularly for shipping, aviation and trucking. This may be due in part to a lack of previous efforts to do such consistency-checking and “bench-marking.” We find that the four models differ in terms of the relative roles of various mitigation strategies to achieve a 2 °C/450 ppm target: the economics-based integrated assessment models favor the use of low carbon fuels as the primary mitigation option followed by efficiency improvements, whereas transport-only and expert-based models favor efficiency improvements of vehicles followed by mode shifts. We offer recommendations for future modeling improvements focusing on (1) reducing data gaps; (2) translating the findings from this study into relevant policy implications such as gaps of current policy goals, additional policy targets needed, regional vs. global reductions; (3) modeling strata of demographic groups to improve understanding of vehicle ownership levels, travel behavior, and urban vs. rural considerations; and (4) conducting coordinated efforts in aligning historical data, and comparing input assumptions and results of policy analysis and modeling insights.     

Integrating GIS concepts into transportation network data structures

Transportation network data structures must be designed to meet the requirements of the analyses being conducted and must be compatible with the selected graphical user interface. Increasing interest in geographic information systems (GIS) and intelligent transportation systems (ITS) have further burdened the network data structure. It is possible to implement object oriented programming (OOP) technology to satisfy these needs, without making the data structure excessively complicated.

This paper shows how a well‐developed network data structure can incorporate major capabilities normally associated with stand‐alone GIS's. The design of a network data structure derives from both theoretical and practical considerations. A design of a network data structure, composed entirely of objects, is presented. Examples of its implementation, limitations, advantages, and possible extensions are drawn from experience with the General Network Editor (GNE).     

Experimental evaluation of CAM and DENM messaging services in vehicular communications

The Cooperative Awareness Basic Service and Decentralized Environmental Notification Basic Service have been standardized by the European Telecommunications Standards Institute (ETSI) to support vehicular safety and traffic efficiency applications needing continuous status information about surrounding vehicles and asynchronous notification of events, respectively. These standard specifications detail not only the packet formats for both the Cooperative Awareness Message (CAM) and Decentralized Environmental Notification Message (DENM), but also the general message dissemination rules. These basic services, also known as facilities, have been developed as part of a set of standards in which both ISO and ETSI describe the Reference Communication Architecture for future Intelligent Transportation Systems (ITS). By using a communications stack that instantiates this reference architecture, this paper puts in practice the usage of both facilities in a real vehicular scenario. This research work details implementation decisions and evaluates the performance of CAM and DENM facilities through a experimental testbed deployed in a semi-urban environment that uses IEEE 802.11p (ETSI G5-compliant), which is a WiFi-like communication technology conceived for vehicular communications. On the one hand, this validation considers the development of two ITS applications using CAM and DENM functionalities for tracking vehicles and disseminating traffic incidences. In this case, CAM and DENM have demonstrated to be able to offer all the necessary functionality for the study case. On the other hand, both facilities have been also validated in a extensive testing campaign in order to analyze the influence in CAM and DENM performance of aspects such as vehicle speed, signal quality or message dissemination rules. In these tests, the line of sight, equipment installation point and hardware capabilities, have been found as key variables in the network performance, while the vehicle speed has implied a slight impact.     

Density/Flow reconstruction via heterogeneous sources and Optimal Sensor Placement in road networks

This paper addresses the two problems of flow and density reconstruction in Road Transportation Networks with heterogeneous information sources and cost effective sensor placement. Following a standard modeling approach, the network is partitioned in cells, whose vehicle densities change dynamically in time according to first order conservation laws. The first problem is to estimate flow and the density of vehicles using as sources of information standard fixed sensors, precise but expensive, and Floating Car Data, less precise due to low penetration rates, but already available on most of main roads. A data fusion algorithm is proposed to merge the two sources of information to estimate the network state. The second problem is to place sensors by trading off between cost and performance. A relaxation of the problem, based on the concept of Virtual Variances, is proposed and solved using convex optimization tools. The efficiency of the designed strategies is shown on a regular grid and in the real world scenario of Rocade Sud in Grenoble, France, a ring road 10.5 km long.     

Relationships Between US Consumer Expenditures on Communications and Transportation Using Almost Ideal Demand System Modeling: 1984–2002

Abstract

This study analyzes aggregate consumer expenditure data from the US between 1984 and 2002, to determine relationships between expenditures on transportation and communications. We first identified 15 categories of goods – nine for transportation, five for communications, and one for all others – and obtained prices for each category across time. Then, we applied the linear approximate almost ideal demand system (AIDS) method for estimating consumer demand functions, aggregating the categories to six (non-personal vehicle (PV), PV capital, PV operation, electronic communications media, print communications media, and all others) due to the small sample size. The results indicate that transportation and communications categories have both substitution and complementarity relationships. The existence of effects in both directions (substitution and complementarity) is testimony to the complexity of the relationships involved, with both generation and replacement possible and happening simultaneously. In addition, expenditures in the transportation categories are generally more income-elastic and price-elastic than those in communications, indicating that communications expenditures are more essential than those for travel. The transportation categories have both substitution and complementarity relationships with each other, while the two communications categories have a substitution relationship.     

Granger-causality between transportation and GDP: A panel data approach

This paper investigates the Granger-causality relationship between income and transportation of EU-15 countries using a panel data set covering the period 1970–2008. In the study, inland freight transportation per capita in ton-km (TRP), inland passenger transportation per capita in passenger-km (PAS), and road sector gasoline fuel consumption per capita in kg of oil equivalent (GAS) are used as transportation proxies and GDP per capita is used as measure of income. Our findings indicate that the dominant type of Granger-causality is bidirectional. Instances of one-way or no Granger-causality were found to correspond with countries with the lowest income per capita ranks in 1970 and/or in 2008. Although we conclude that there is an endogenous relationship between income and transportation, this is not observed until after an economy has completed its transition in terms of economic development.     

Improving estimates of transportation emissions: Modeling hourly truck traffic using period-based car volume data

We estimate hourly truck traffic using period-based car volumes that are usually available from travel demand models. Due to the lack of local or regional data, default vehicle-miles traveled mix by vehicle class in mobile emission inventory models is usually used in transportation emissions inventory estimates. Results from such practice, however, are often far from accurate. Heavy-duty trucks generate orders of magnitudes higher emission rates than light duty vehicles. Vehicle classification data collected from weigh-in-motion stations in California are used to examine the performance of various forms of the method across days of week and geographic areas. We find that the models identified provide satisfactory and statistically robust estimates of truck traffic.