Fluctuation analysis of M25 loop data

Abstract

Abstract

By calculating exponents relating to the flow velocity of traffic on the M25 motorway in the United Kingdom, evidence is given for scale-free behaviour in the dynamics of traffic at near-capacity flow. Specifically, it is demonstrated that during periods of high demand the flow is well described by a strongly antipersistent fractional Brownian motion. This approach to traffic flow analysis provides a robust and accurate quantitative characterization of the flow which can be used to inform choices of traffic flow prediction methods. Additionally, the quantities calculated here can be used to assess the performance of individual-based traffic simulation models which are finding increasingly widespread use as a means of understanding the impact of potential modifications to motorway networks.