"An island is a defined area between traffic lanes used for control of vehicle movements, Islands also provide an area for pedestrian refuge and traffic control device. Within an intersection, a median or an outer separation is also considered an island. This definition makes it evident that an island is no single physical type. It may range from an area delineated by raised curb to a pavement area marked out by paint . . . Where traffic entering an intersection is directed into definite paths, this design feature is termed a channelized intersection."