Rectangle-Clipping Algorithm of Time to Collision for Freeway Traffic Simulation

To simulate the traffic on freeway, the stimulus which would influence the drivers' behavior should be quantified. To a certain extent drivers' behavior is dependent on the environmental vehicles' status. In this paper, such influence is quantified by the time to collision. The simulation system is developed in a 2-dimension continuous coordinates system in which the trajectory is continuous and computation cost is larger than general simulation models, which makes the improvement of the algorithm efficiency very necessary. Due to the fact that the relative speed is usually considerable, the dimensions of the vehicles should not be ignored in the collision time calculation. As a result, the calculation process will be a numerical simulation process in which the collision detection algorithm should be applied. A rectangle clipping algorithm is developed and tested for the simulation system in this research.