Identifying Features of Traffic Hysteresis on Freeways

Traffic hysteresis is a characteristic of congested traffic and may have significant implications on freeway traffic operations.Hysteresis is analyzed through vehicle trajectories on both a macroscopic and a microscopic level. Instances of traffic hysteresis are detected and categorized. Then, their macroscopic and microscopic traffic flow characteristics are estimated and statistically investigated using artificial neural networks. Analyses reveal that changes in spacing and acceleration at the end of the phenomenon appear to be the most critical determinants of driver behavior. Different determinants of hysteresis for aggressive as well as timid drivers are investigated, quantified and compared.