|
|
发表于 2005-12-17 19:55:32
|
显示全部楼层
[推荐] Physics Reports 上关于交通流理论研究的两篇最新评述文章
今年Physics Reports 有两篇关于交通流理论的综述，都涉及到元胞自动机模型，比较详尽。下面是相关的信息。
《Probabilistic descriptionof traffic flow》
R. Mahnkea, J. Kaupužs, I. Lubashevsky
Physics Reports 408 (2005) 1–130
Abstract
A stochastic descriptionof traffic flow, called probabilistic traffic flow theory, is developed. The general master equationis applied to relatively simple models to describe the formationan d dissolutionof traffic congestions.Our approach is mainly based on spatially homogeneous systems like periodically closed circular rings without on- and off-ramps. We consider a stochastic one-step process of growth or shrinkage of a car cluster (jam). As generalization we discuss the coexistence of several car clusters of different sizes. The basic problem is to find a physically motivated ansatz for the transition rates of the attachment and detachment of individual cars to a car cluster consistent with the empirical observations in real traffic. The emphasis is put on the analogy with first-order phase transitions and nucleation phenomena in physical systems like supersaturated vapour. The results are summarized in the flux–density relation, the so-called fundamental diagram of traffic flow, and compared with empirical data.Different regimes of traffic flow are discussed: free flow, congested mode as stop-and-go regime, and heavy viscous traffic. The traffic breakdownis studied based onthe master equationas well as the Fokker–Planck approximation to calculate mean first passage times or escape rates. Generalizations are developed to allow for on-ramp effects.The calculated flux–density relation and characteristic breakdown times coincide with empirical data measured on highways. Finally, a brief summary of the stochastic cellular automata approach is given.
《Cellular automata models of road traffic》
Sven Maerivoet, Bart De Moor
Physics Reports 419 (2005) 1 – 64
Abstract
In this paper, we give an elaborate and understandable review of traffic cellular automata (TCA) models, which are a class of computationally efficient microscopic traffic flow models. TCA models arise from the physics discipline of statistical mechanics,having the goal of reproducing the correct macroscopic behaviour based on a minimal description of microscopic interactions. After giving an overview of cellular automata (CA) models, their backgroundandphysical setup, we introduce the mathematical notations,show how to perform measurements on a TCA model’s lattice of cells, as well as how to convert these quantities into real-world units andvice versa. The majority of this paper then relays an extensive account of the behavioural aspects of several TCA models encountered in literature. Already, several reviews of TCA models exist, but none of them consider all the models exclusively from the behavioural point of view. In this respect, our overview fills this void, as it focusses on the behaviour of the TCA models,by means of time–space and phase-space diagrams, and histograms showing the distributions of vehicles’ speeds, space, and time gaps. In the report, we subsequently give a concise overview of TCA models that are employedin a multi-lane setting, andsome of the TCA models used to describe city traffic as a two-dimensional grid of cells, or as a road network with explicitly modelled intersections. The final part of the paper illustrates some of the more common analytical approximations to single-cell TCA models. |
|
IP卡
狗仔卡
提升卡
置顶卡
沉默卡
喧嚣卡
变色卡
显身卡
