Effects of edge rate of the designed line markings on the following time headway

Time headway is an important indicator for evaluating car-following safety. To study the in uence of edge rate on time headway in car-following, three patterns of line marking were designed and placed on a real-world expressway, with actual vehicle ow data collected. Statistical analyses showed that (1) Time headways raised after the installation of line markings compared with the original situation; and (2) When the value of edge rate fell in [5 Hz,14 Hz], the time headway rose along the increase in the edge rate.
Furthermore, the increases in time headways were interpreted in relation with the leveling up of the driver's risk perception due to its overestimation in speed and underestimation in distance caused by edge rate. The nding of this study suggests that the designed line markings may bene t engineers and decision makers in providing them with a new approach to cope with critical issues in trac safety.