有限理性视野下网络交通流逐日演化规律研究∗

摘要

The formation mechanism of network traffic flow and its evolution law are closely related to daily activities of travelers. The current studies indicate that the law of network traffic flow evolution is day-to-day;therefore, using days as the scale unit is an important way to illustrate the evolution of network traffic flow. In previous studies, travelers in the network were tacitly assumed to be entirely rational. When the rationality of travelers is limited, the dynamics of the evolution law needs to be re-examined. This paper presents the utility maximization hypothesis in a logit model by using the “bounded rationality” hypothesis and develops a bounded rational binary logit (BRBL) model. We apply the BRBL model to a day-to-day network traffic flow distribution and discuss the evolution law of day-to-day network traffic flow under the assumption of the limited rationality of travelers. Through a numerical experiment, this paper analyzes the evolution characteristics of network traffic flow. The results are as follows. Firstly, the final state of the network traffic flow process is not only correlated to the cost-sensitivity of travelers and dependence on actual cost, but also strongly related to the degree of the nationality of travelers. Secondly, the system will be either bifurcated or chaotic when either cost-sensitivity increases or dependence on actual cost increases. Moreover, within the group of travelers whose rationality level is low, no matter what the cost-sensitivity of travelers and the dependence on actual cost are, the evolution results are asymptotically stable. Finally, in particular, in certain circumstances, it is easy to achieve stability when the rationallty degree of travelers is very high or very low, while it is not easy to achieve stability when the rationality degree of travelers is medium.%基于有限理性的前提假设，建立了“有限理性二项logit”模型，用以描述出行者路径选择行为，并以一个由2条路径构成的路网为例，探讨了理性程度不同群体的网络交通流逐日动态演化过程。通过数值实验，分析了网络交通流的演化特征，发现网络交通流演化最终状态除了与出行者群体对费用的敏感程度、对实际费用的依赖程度有关，还与出行者群体的理性程度有很大关系。在一定的情况下，出行者理性程度很高或很低均可以使系统稳定，而恰恰是理性程度一般的群体不容易达到稳定。