This paper analyzes safety at traffic roundabouts with a comparison between conventional lane marking and Alberta-type marking. A cell-based model is developed where the spatial and temporal dimensions are discretized into cells and time intervals. Based on the assumption of independent vehicular movements, a potential conflict is alleged to evolve when two or more vehicles are projected to collide into the same cell at the same time interval. Such potential conflict counts are subsequently used as a measure for quantitatively assessing the safety level of the roundabout. Our results show no significant difference between the safety level for conventional marking and for Alberta-type marking. However, the conflicts of Alberta-type marking tend to centralize at a few black spots. (Author/publisher)
Samenvatting