A cellular automata traffic flow model with spatial variation in the cell width

Abstract This paper addresses a practical problem in road transportation regarding how the arrangement of three-dimensional facilities on a road (e.g., toll stations, construction guardrails and safety cones) will affect driving behavior. According to literature research and site investigations, in most cases, such facilities cause drivers to perceive a certain level of variation in the lane width, which will ultimately affect their driving behavior. For example, a driver will control a vehicle more carefully when approaching such a facility and usually reduce the passing speed according to his/her perception and experience. To the best of our knowledge, however, few related numerical studies and corresponding practical test cases have been reported at present. This paper uses a cellular automata traffic flow model to analyze this traffic problem. Notably, the existing models of this kind do not consider the cell width and its effect on vehicle speed. Motivated by the above problems and based on the human eye imaging principle, the dynamic visual field mechanism and test data, the present work first proposes a numerical relationship among the vehicle speed, the distance to the target and the perceived width of a fixed facility alongside the lane. Then, a new cellular automata traffic flow model with spatial variation in the cell width is designed to correlate the cell shape variable with the perceived width of the lane. Simulations based on this new model are conducted to simulate and compare the statuses of vehicles in a single lane with and without fixed facilities. The simulation results show that the speed reduction caused by cell deformation has a significant influence on the flow of traffic and that a “gate” effect occurs in deformed cells, resulting in behavior close to actual traffic phenomena. However, as the traffic density increases, the influence of deformed cells on a vehicle’s movement lessens. The proposed model may be a meaningful extension of cellular automata traffic flow models.