A Cellular Automata simulation for traffic flow on multi-lane freeways under various control rules

To analyze several traffic indices dynamically and explore the relationship among the indices, a model for multi-lane freeway traffic based on Cellular Automata (CA) theory is proposed in this paper. In the proposed model, vehicle movement is categorized into cellular behavior as chasing, overtaking, changing lane, accelerating and decelerating, cellular status is categorized into velocity change and position change, and a set of cellular behavior constraints have been made based on the keep-right-except-to-pass rule and a revised rule allowing freely changing-lane. The main advantages of the proposed model include: the number of lanes is variable so the model is flexible for multi-lane road; a new road initialization method is adopted and capable of dealing with entering lanes in different probabilities. Matlab software package is used to simulate and calculate different indices including traffic flow, safety, and traffic density under different rules, safety conditions, traffic flow conditions and degree of road congestion. Finally, a number of experiments based on the established model were performed to explore the influence of model parameters (e.g., overtaking rules and speed limit) on of traffic indices and the results of the experiments are analyzed and discussed in detail.