Abstract:
In a previous research, a wide range of skewed angles was verified using a static model, between the two roads in an intersection, that could be dangerous. Simplified intersection geometries were used, vehicle dimensions that may have influence to the lateral visibility phenomenon were measured and sight angles from rear-view mirrors were also measured experimentally. This research aims to take into account some dynamical variables, specially related to the drivers' behavior, to study the right turn maneuvers within an intermediate skew angle and to study the effect of the skew angle on safety. Field observations of the drivers behavior, their visual scanning process and the vehicles evolution, while right turn maneuvering, were carried out using video recording. Specific software was developed for tracking vehicle trajectories and to register driver behavior, based on field videos. This research aims to relate the right turn lanes geometry with the vehicle trajectories, the driver scanning process, and the main street traffic volume. The information was analyzed statistically to explain the observed drivers’ behavior and evaluate road safety criteria. Microsimulation software was developed to facilitate evaluation for both new designs and current right turn maneuvers. This microsimulation software takes into account the drivers' visibility limitations as well as the layout geometry. As a geometric design criteria, new right turn lane should be designed using a right turn slip lane with a high entry angle (more than 70º), to improve visibility and to enforce drivers to reduce speed before entering.
