Driving on the left or right

Keeping to either the left or the right prevents vehicles moving in opposite directions from colliding with each other. This is so fundamental that it is sometimes known simply as the rule of the road. 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, even though originally most traffic drove on the left worldwide.