Abstract
This paper proposed a new approach to evaluating collision risk of multiple car-following vehicles based on microscopic shockwave propagation theory. Macroscopic traffic flow “q” and density “k” are proved to be transformed into the microscopic variables such as inverse of time headway and that of spacing between vehicles. Speed difference weighted by the spacing between vehicles is proved to be the microscopic shockwave speed and used as the collision risk index of three-vehicle car-following. The applicability of the proposed approach is evaluated through real-world car-following data observed at a test track.
