Influence of Discontinuous Line Markings on Time Headway Distribution in Car-Following

Insufficient time headway is an important reason for rear-end collisions. To prevent this type of accident, a series of discontinuous line markings were installed on the surface of the slow lane of a real-world expressway in China. Statistical analyses showed that, after the installation of discontinuous line markings, 1) the mean time headway was increased, 2) the time headway distributions were relatively concentrated as compared to the control where no extra line marking was installed, and 3) the proportion of low time headway reduced while the proportion of high time headway increased. The results suggest that the discontinuous line markings may increase time headway in car-following and enhance the stability of car-following flows. This may provide the decision makers and engineers a new method in coping with issues concerning traffic safety.