Real-time freeway traffic state estimation based on extended Kalman filter: Adaptive capabilities and real data testing

This paper reports on real data testing of a real-time freeway traffic state estimator, with a particular focus on its adaptive capabilities. The pursued general approach to the real-time adaptive estimation of complete traffic state in freeway stretches or networks is based on stochastic macroscopic traffic flow modeling and extended Kalman filtering. One major innovative feature of the traffic state estimator is the online joint estimation of important model parameters (free speed, critical density, and capacity) and traffic flow variables (flows, mean speeds, and densities), which leads to three significant advantages of the estimator: (1) avoidance of prior model calibration; (2) automatic adaptation to changing external conditions (e.g. weather and lighting conditions, traffic composition, control measures); (3) enabling of incident alarms. These three advantages are demonstrated via suitable real data testing. The achieved testing results are satisfactory and promising for subsequent applications.     

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经过规范化的发展,已经涌现出不少成熟的企业信息集成(EII)模型,而城市交通信息集成（UTII）方面还缺乏规范、成熟的模型。基于此,本文从流程再造、数据交互以及数据挖掘三个方面,提出了一种城市交通信息集成三维模型（3D-UTII)。这三个维度的集成即为：基于流程再造的交通信息系统内部的深度集成（DDII）,基于异构数据库技术的交通信息系统间的广度集成（EDII）,以及基于数据挖掘技术的分析式集成（ADII）。本文对这三个维度的实施框架和具体实现技术分别做出了进一步阐述,最后使用北京市奥运交通应急系统的信息集成方案为实例对模型的实施做出了说明和验证。     

公路交通量调查数据分析

根据盘锦地区历年路段交通量实地调查统计资料,对公路交通量增长趋势、混合交通量组成以及表示交通量变化规律的特征值做了分析,并阐明了交调资料对地方公路建设规划的作用.     

A framework for travel time variability analysis using urban traffic incident data

This study aims to develop a framework to estimate travel time variability caused by traffic incidents using integrated traffic, road geometry, incident, and weather data. We develop a series of robust regression models based on the data from a stretch in California's highway system during a two-year period. The models estimate highway clearance time and percent changes in speed for both downstream and upstream sections of the incident bottleneck. The results indicate that highway shoulder and lane width factor adversely impact downstream highway clearance time. Next, travel time variability is estimated based on the proposed speed change models. The results of the split-sample validation show the effectiveness of the proposed models in estimating the travel time variability. Application of the model is examined using a micro-simulation, which demonstrates that equipping travelers with the estimated travel time variability in case of an incident can improve the total travel time by almost 60%. The contribution of this research is to bring several datasets together, which can be advantageous to Traffic Incident Management.     

工字钢组合梁架空设备稳定性检算及应用

主要介绍了在营业线架空线路施工中常用的工字梁安全稳定性的检算依据、方法,并用实例进行了计算,对其应用条件、特点及改进措施作了阐述。     

有交通条件约束与软时间窗约束的配送配载模型算法研究

由于配送中客户的时间窗限制和车辆在运行过程中的交通条件约束，给配送中心的运营调度工作增加了新的难题，为此建立了在该约束条件下的车辆配送配载模型。通过在路径选择时考虑交通条件约束、在建立目标函数时以阈值的形式引入时间窗约束，对原始模型进行了拓展，并构造了该问题的遗传算法。     

试论水上交通事故责任认定的不可诉性

对水上交通事故责任认定不服,是否可以提起行政复议或者行政诉讼这一问题,在海事管理机构内部一直持有不同的观点。文章通过对法学的理解,分析了水上交通事故责任认定的特点、行政行为的法理分类和司法判例等诸多方面,提出不服水上交通事故责任认定不宜通过行政诉讼途径解决的观点。     

单线列车运行调整的最早冲突优化方法

针对单线铁路列车运行调整问题的特点,建立单线列车运行调整的数学模型,提出最早冲突优化方法。该方法首先生成松弛运行调整计划,再对松弛计划中的冲突逐一选择最早冲突优先化解,松弛计划中的全部冲突得以序列化化解后获得阶段计划。最早冲突优化方法克服了组合化解冲突产生的巨大方案数,具有较高的运行效率。实例证明最早冲突优化方法生成的阶段计划质量高、运算快,完全能满足行车调度的实时性要求。