双车道元胞自动机NS和WWH交通流混合模型的研究

考虑不同车辆的驾驶员有不同的驾驶方式和习惯，具体表现为不同的驾驶员采用适合自己行车特点的交通流模型在道路上驾车行驶，在一维元胞自动机交通流NS模型和WWH模型的基础上，建立了双车道元胞自动机NS和WWH交通流混合模型. 通过计算机模拟，给出了混合比例系数f_NS对混合交通流的速度-密度和流量-密度图以及车辆转道频率影响的结果. 关键词： 双车道 元胞自动机 混合交通流模型 计算机数值模拟     

考虑公交港湾式停靠的多速混合城市交通流元胞自动机模型研究

在Nagel-Schreckenberg提出的元胞自动机模型基础上,建立了考虑公交车辆和港湾式公交停靠站的多速混合车辆单车道城市交通流元胞自动机模型.通过计算机模拟,给出了随机减速概率、混合车流密度、公交车辆平均停靠时间、公交车辆占有率和港湾式公交车站间距对混合车流速度和流量的影响图.对混合车流的特性进行了分析和讨论. 关键词： 元胞自动机 港湾式公交停靠站 混合交通流模型 计算机模拟     

开放边界条件下二维可转向主干道交通流模型的研究

在开放性边界条件下，利用改进的Nagel-Schreckenberg交通流模型，引入过路口车辆的可 转向机理，建立二维n速主干道元胞自动机交通流模型，研究了转向概率和边界条件对 干道交通状况的影响而导致的不同相变特性以及这两个因素对实现改善干道交通的组织作用 . 关键词： 元胞自动机 交通流 转向概率 相变     

元胞自动机混合交通流模型的能耗研究

基于元胞自动机交通流NaSch模型,提出元胞自动机混合交通流能耗公式,对混合交通流的能耗进行研究,通过数值模拟研究不同最大速度、不同车长的混合交通流的能耗;研究表明不同车长、不同最大速度以及混合比对混合交通流能耗均有不同的影响. 关键词： 交通流 元胞自动机 能耗 混合交通     

多速混合车辆单车道元胞自动机交通流模型的研究

在交通流NS模型的基础上，建立了多速混合车辆单车道元胞自动机交通流模型， 通过计算机数值模拟，得到了混合车辆在不同参数下交通流模型的基本图，并对混合交通的 特性进行了分析和讨论. 关键词： 元胞自动机 混合交通流模型 计算机模拟     

考虑驾驶员特性的一维元胞自动机交通流模型

在一维元胞自动机交通流WWH模型和SDNaSch模型的基础上,建立了一种考虑驾驶员特性的元胞自动机交通流模型(Driver-SDNaSch模型).该模型将驾驶员分为激进型、保守型和中立型三类,根据其不同的驾驶特性制定了各自的演化规则,并以此对其进行状态更新;同时考虑了前车速度为0的情况,引入安全减速概率.通过计算机对Driver-SDNaSch模型进行模拟,给出了由三类驾驶员按不同比例组成的混合交通流的速度-密度图和流量-密度图,并对此类混合交通流的特性进行了分析和讨论.与NaSch模型和SDNaSch模 关键词： 交通流 元胞自动机 驾驶员特性 计算机数值模拟     

双向两车道混合车辆交通流的特性

在NaSch模型的基础上，制订了超车规则，建立了双向两车道混合车辆的元胞自动机交通流模型. 用计算机模拟了车道密度对称和不对称两种情况下不同参数的混合车辆交通流，得出了相应的速度、流量与密度关系的基本图. 经分析发现，双向两车道混合车辆交通状态可分为快车特性区、准慢车特性区和慢车特性区；两车道上车辆密度的不对称性对交通流有重要的影响. 关键词： 元胞自动机 交通流 混合车辆交通流     

一维确定性主干道交通流模型的研究

利用一维确定性元胞自动机模型模拟主干道交通流 ,研究绿信比、道路上车辆密度、周期、交通灯的多少对主干道交通流流量和流速的影响     

一种考虑速度随机慢化概率动态演化的交通流元胞自动机模型

在NS模型的基础上,利用司机的记忆效应和当前交通环境动态地调整随机慢化概率,从而得到一个改进的交通流元胞自动机模型.数值实验表明,该模型可以很好地刻画司机记忆效应对交通流的影响,记忆效应的引入可以提高平均速度和流量. 关键词： 交通流 元胞自动机模型 记忆效应 随机慢化概率     

基于agent的城市过境交通流模型

在Biham等人提出的二维元胞自动机交通流模型基础上,建立了基于agent的二维元胞自动机城市交通流模型,该模型考虑了对外交通对城市交通流的影响。模拟了在存在对外交通概率情况下路网的结构对城市交通的影响.结果表明,较小的对外交通概率就会对城市交通状况产生较大的影响,在一定条件下适当增加中心车站的数量对城市交通状况有所改善。     

A study of a main—road cellular automata traffic flow model

A main-road cellular automata traffic flow model on two dimensions is presented based on the Biham－Middleton－Levine traffic model. Its evolution equations are given and the self-organization and organization cooperation phenomena in this model are also studied by using computer simulation.     

智能交通灯对交叉路口交通流的影响

以改进的NaSch模型为基础,采用开放边界条件,分别对普通交通灯和智能交通灯控制下的十字交叉路口交通流进行模拟.结果表明,主干道车辆较多时,智能交通灯控制下的主干道车辆平均速度和流量都比普通交通灯控制下高,并可减少车辆的无谓等待时间. 关键词： 元胞自动机 交叉路口 智能交通灯 NaSch模型     

Characteristics of synchronized traffic in mixed traffic flow

In this paper, the characteristics of synchronized traffic in mixed traffic flow are investigated based on the braking light model. By introducing the energy dissipation and the distribution of slowdown vehicles, the effects of the maximum velocity, the mixing ratio, and the length of vehicles on the synchronized flow are discussed. It is found that the maximum velocity plays a great role in the synchronized flow in mixed traffic. The energy dissipation and the distribution of slowdown vehicles in the synchronized flow region are greatly different from those in free flow and a traffic jamming region. When all of vehicles have the same maximum velocity with V max > 15, the mixed traffic significantly displays synchronized flow, which has been demonstrated by the relation between flow rate and occupancy and estimation of the cross-correlation function. Moreover, the energy dissipation in the synchronized flow region does not increase with occupancy. The distribution of slowdown vehicles shows a changeless platform in the synchronized flow region. This is an interesting phenomenon. It helps to deeply understand the synchronized flow and greatly reduce the energy dissipation of traffic flow.     

An improved cellular automaton model considering the effect of traffic lights and driving behaviour

This paper proposes an improved cellular automaton model to describe the urban traffic flow with the consideration of traffic light and driving behaviour effects. Based on the model,the characteristics of the urban traffic flow on a single-lane road are investigated under three different control strategies,i.e.,the synchronized,the green wave and the random strategies. The fundamental diagrams and time-space patterns of the traffic flows are provided for these strategies respectively. It finds that the dynamical transition to the congested flow appears when the vehicle density is higher than a critical level. The saturated flow is less dependent on the cycle time and the strategies of the traffic light control,while the critical vehicle density varies with the cycle time and the strategies. Simulated results indicate that the green wave strategy is proven to be the most effective one among the above three control strategies.     

交通灯控制下主干道的交通流研究

用元胞自动机模型模拟二维交通流.通过交叉口设置的红绿灯，研究交通激波的形成和传播 ；对于一定的红绿灯周期，交通流量出现多个极值现象；在交叉口间隔相同的情况下，对于 一定的红绿灯周期，在一定的车辆密度范围内，交通流量是一个与密度无关的常量；在车辆 密度较高的情况下，交叉口间距大于某一值后，交通流量保持恒定值. 关键词： 元胞自动机模型 交通流 交通激波     

混合状态下城市快速路交通流短时预测

建立交通流短时预测状态空间模型, 研究混合状态下城市快速路交通流短时预测. 结合城市快速路自由流状态、拥挤流状态和阻塞流状态下交通流参数的时间和空间分布特性, 基于交通流守恒方程和速度动态模型, 借鉴偏微分方程组求解时空离散的思想, 建立三种状态下交通流短时预测模型; 同时考虑进出口匝道、车道数变更以及道路坡度等因素的影响, 将交通流短时预测模型转化为交通流短时预测状态空间模型, 实现混合状态下交通流短时预测. 研究表明, 该方法能够实现混合状态下道路网内的交通流短时预测, 预测精度可达90.23%. 相同条件下, 经典自回归滑动平均模型的预测精度仅为81%. 关键词： 交通流短时预测 自由流状态 拥挤流状态 阻塞流状态     

Synchronized traffic flow simulating with cellular automata model

The synchronized flow traffic phase of Kerner’s three-phase traffic theory can be well reproduced by the model proposed by Jiang and Wu [R. Jiang, Q.S. Wu, J. Phys. A: Math. Gen. 36 (2003) 381]. But in the Jiang and Wu model, the rule for brake light-after switching on, the brake light will not set off until the vehicle accelerates-is obviously unrealistic. Thus we improved the model by considering the difference in accelerating and decelerating performance under different driving conditions. The fundamental diagram and spatial-temporal diagrams are analyzed. We confirmed that the new model could reproduce the synchronized flow by two methods, i.e. the traffic flow interruption effect and performing microscopic analysis of time series data. Simulation results show that the decelerating difference is an important factor to reproduce the synchronized flow. We expect that our work could make contributions to understanding the mechanism of the synchronized flow.     

Noise at the approach to traffic lights: Result of a simulation programme

This paper describes a computer model of the acoustic behaviour of road traffic at the approach to a system of traffic lights. The outputs of this model consist of various acoustic signatures of the traffic at different points along the roadside. These signatures are a good approximation to those determined at real locations under similar conditions. Use of the model leads to a better understanding of the phenomena involved and the derivation of laws as a function of parameters such as traffic flow, speed limits, proportion of heavy vehicles and the traffic light cycles and synchronization.     

A traffic noise prediction method based on vehicle composition using genetic algorithms

The effect of traffic composition on the noise pollution has been investigated in a small city Erzurum, located in eastern Turkey, where the population is about 400,000. Manual noise measurements and vehicle counts were performed at the four heaviest traffic points in the city for a period of 12 h. Using the information on vehicle composition and the maximum legal noise emissions of each type of vehicles, two prediction models based on genetic algorithms have been developed that can be used as tools for in-city traffic flow redesign. The models have been validated against some of the noise data. Measured traffic noise levels have been compared with predictions using the new models and some existing ones and a relatively good agreement has been obtained between them.