History of roads in Ireland

There have been routes and trackways in Ireland connecting settlements and facilitating trade since ancient times and the country now has an extensive network of public roads connecting all parts of the island.

The first routes in Ireland were prehistoric trackways, some of which were later developed into roads suited for wheeled vehicles. Many of Ireland's minor roads "may well have had their origin in pre-existing paths and trackways aligned in direct response to the physical environment". Traces of these evolved roads which developed over very long periods, frequently from tracks of the prehistoric period, are still evident. The routes of such roads usually followed the natural landscape, following the tops of ridges and crossing rivers and streams at fording points.

Wikipedia