An interchange is also a type of road junction. It is distinct from the more generic 'junction' or 'intersection' in that it indicates (in the United States, at least) a structure joining two or more roadways using multiple levels of grade so that traffic can pass through the interchange on at least one of the intersecting roadways without slowing or stopping. In the United States, this is generally done with exit and entrance ramps, with the (usually) two highways separated vertically by either raised roadway bridges or by having one road pass through a cutout to lower it below ground level at the point of intersection.