Platoon Dispersion and Saturation Flow Rates in Cellular Automata Models of Signal-Controlled Roadway Traffic

Cellular automata (CA) models of traffic flow have been used in many applications, including numerous studies of traffic signal control, but little attention has been given to the calibration of these models for analysis of interrupted traffic flow performance. This paper examines platoon dispersion and saturation flow rates in CA models that consider constant and variable probability p of random vehicle slowing. The constant p model exhibits unrealistic platoon dispersion behavior, and a wide range of saturation flow rates. The variable p model achieves more realistic platoon dispersion and exhibits a more reasonable range of saturation flow rates. The rate of increase in p is found to be an important parameter for calibration in the variable p model, impacting both saturation flow and platoon dispersion. The results offer a starting point for development of more comprehensive CA model calibration in future work.