组合匝道瓶颈下交通流相变研究  

Research on traffic flow phase transition at combined ramp bottleneck

作　　者：胡河森 靳文舟[1] HU Hesen;JIN Wenzhou(School of Civil and Transportation Engineering,South China University of Technology,Guangzhou 510641,China)

机构地区：[1]华南理工大学土木与交通学院,广东广州510641

出　　处：《广西大学学报（自然科学版）》2023年第5期1104-1115,共12页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金项目(52072128)。

摘　　要：针对组合匝道瓶颈附近发生的交通崩塌现象,提出了概率论主方程模型用以描述该现象。基于三相交通流理论,分析得出初始非均匀自由流中交通崩塌现象发生的本质是自由流到同步流的一阶相变,同时假设了一个确定性的局部扰动始终位于瓶颈附近,该扰动造成了过加速效应对于速度适应效应的竞争劣势。然后构建了合适的概率论主方程模型,并进一步推导得到了交通拥堵的平均迟滞时间和相变概率的表达式。理论结果的进一步分析表明:入口匝道流量的增加将加快交通流相变的进程,出口匝道流量对维持交通流的稳定性有促进作用,并且主干道流量对自由流波动影响较小,因此控制入口匝道流量的汇入对维持组合匝道瓶颈处初始自由流的稳定性非常重要。A master equation model is proposed to describe the traffic breakdown phenomenon occurring near the bottleneck of the combined ramp.Based on the three-phase traffic flow theory,it is shown that the nature of the traffic breakdown phenomenon in the initial non-uniform free flow is a first-order phase transition from free flow to synchronous flow,and a deterministic local disturbance is assumed to be always located near the bottleneck,which causes a competitive disadvantage of the over-acceleration effect over the speed adaptation effect.Then a suitable probabilistic master equation model is constructed and further derived to obtain expressions for the average delay time and phase transition probability of traffic congestion.Further analysis of the theoretical results shows that the increase of on-ramp flow will accelerate the phase transition of traffic flow,and the off-ramp flow contributes to maintaining the stability of traffic flow as well as the flow from upstream of the bottleneck has less effect on the fluctuation of free flow,so it is important to control the convergence of the on-ramp flow to maintain the stability of the initial free flow at the combined ramp bottleneck.

关 键 词：相变 三相交通流理论 组合匝道瓶颈 主方程 

分 类 号：TU473.1[建筑科学—结构工程]