Nothing contained in this chapter shall be construed as limiting the complete freedom of movement, into, out of or within the demilitarized zone, of the Joint Commission, its joint groups, the International Commission to be set up as indicated below, its inspection teams and any other persons, supplies or equipment specifically authorized to enter the demilitarized zone by the Joint Commission. Freedom of movement shall be permitted across the territory under the military control of either side over any road or waterway which has to be taken between points within the demilitarized zone when such points are not connected by roads or waterways lying completely within the demilitarized zone.