Dutch expressways are built to significantly varying standards. Designs range from fully controlled-access dual carriageways with grade separation, center dividers and full hard shoulders, to single carriageways with just one lane per direction and only intermittent shoulder patches called "Vluchthavens" (small Lay-bys). Intersections are frequently at grade with traffic lights, or they are roundabouts. Although there are never level railway crossings, there can be moveable bridges in these roads. In either case, the speed limit is frequently reduced to 70 km/h before reaching the junction or the bridge.