Traffic Directionality

Traffic directionality refers to regulations requiring all vehicular traffic to keep either to the left or the right side of the road. Whether the right or the left is specified depends on the laws of each country. This is so fundamental to vehicular transport that it is commonly referred to as the rule of the road[1]. The purpose of the rule of the road is to facilitate traffic flow and reduce the likelihood of head-on collisions. About 34% of the world by population drive on the left, and 66% on the right. By roadway distances, about 28% drive on the left, and 72% on the right,[2] even though originally most traffic drove on the left worldwide.