非均衡网络交通流动态演化规律研究

为描述非均衡网络交通流实际成本-流量状态,考虑置存成本和路段行程时间,建立行程时间动态函数,将其引入用户均衡模型,构建基于出行总成本动态、路径流量动态、路段行程时间动态的交通流演化模型。利用简单网络,采用四阶龙格库塔方法对建立的模型进行数值模拟。动态模型弹性需求下,出行成本调整范围由大到小,趋于平衡值;路径流量迅速增加后,以较小调整范围,趋于平衡值;路段行程时间迅速增加后,逐步趋向于平衡值。固定需求下的出行成本、路径流量、路段行程时间均是反复调整多次后趋近于平衡值,调整范围缩小,次数增加。算例模拟结果表明,模型能够描述网络交通流从一种非均衡状态到另一种非均衡状态的动态调整过程。

A Study of the Evolution of Traffic Flow Dynamic of a Disequilibrium Network

To describe the cost-flow relationship of disequilibrium traffic flow,a function for modeling dynamic travel time is established considering the carrying cost and travel time.A flow model of dynamic traffic is developed based on total travel cost,path flow,link travel time and coupled with a user equilibrium model.A numerical simulation is car-ried out using a simple network and the fourth order Runge-Kutta method to test the created model.Under the elastic de-mand of dynamic model,travel cost ranges from large to small,then approaches to an equilibrium value.After a rapid in-crease of path flow,with a smaller adjusting range,it tends to approach to an equilibrium value.After a rapid increase in travel time,it gradually approaches to an equilibrium value.The travel cost of fixed demand,flow path and travel time approach to an equilibrium value after repeating adjustments several times with a small range.The simulation results show that the model can accurately describe the adjustment process of network traffic flow from one disequilibrium statue to another.