In the early centuries of Gondor, Osgiliath was the royal city, and would have been the natural southern terminus of the road. However, our maps of the region (relating to a much later time, at the end Third Age) instead show the North-South Road actually running to Minas Tirith, with an eastward branch then carrying on to Osgiliath (and a southern branch proceeding to Pelargir). This would make sense in the later part of the Third Age, when Osgiliath had been abandoned and Minas Tirith had become the chief city of Gondor. At the time the road was made, however, Osgiliath would have been the main city, and Minas Tirith (then Minas Anor) a lesser fortress tower. Indeed, it is conceivable that the course of the North-South Road was different in earlier times, and that it originally ran directly to Osgiliath.

The original capital of the North-kingdom was at Annúminas, somewhat to the west of Fornost, and it seems inevitable that the two cities would have been linked by a road. This would have formed an extension at the northern end of the North-South Road running westwards for about one hundred miles, though we do not have any direct evidence for its existence.