Empirical Study of Fractal Characteristics of Traffic Time Series

Abstract

In order to analyze the fractal characteristics of traffic flow under synchronized, jam and free conditions, the complexity of traffic flow was depicted by using correlation dimension, the long—term dependence of traffic flow was studied by using Hurst index, and the influence range of traffic flow was delimited by using memory length. The computation result from real traffic data shows that (1) three kinds of traffic flow are fractal and exist long – term dependence; (2) correlation dimension of synchronized traffic flow is smaller than that of jam traffic flow, and correlation dimension of jam traffic flow is smaller than that of free traffic flow; (3) Hurst indexes of synchronized traffic flow and jam traffic flow are larger than that of free traffic flow, memory length of synchronized traffic flow is longer than that of jam traffic flow, and memory length of jam traffic flow is longer than that of free traffic flow. It indicates that different kinds of traffic flow have different fractal characteristics.