This is a togher, the Irish term for a timber trackway laid across wet or boggy ground to allow safe passage where the land itself would otherwise swallow a traveller whole. The example at Derryoghil is a class 3 togher, meaning it was constructed from longitudinal roundwood, the trunks or branches laid lengthways along the line of travel, packed with brushwood of ash and hazel beneath or alongside to provide a stable, slightly springy surface underfoot.

The structure runs on a northwest to southeast orientation, measuring 1.2 metres wide and roughly 0.2 metres deep. Those are modest dimensions, enough for a single person or perhaps a laden animal to pass without sinking, and the choice of ash and hazel is telling. Both are fast-growing, flexible, and were widely managed through coppicing in early medieval and prehistoric Ireland, suggesting the builders had ready access to well-maintained woodland nearby. Toghers of this kind were frequently laid across the midland bogs during the prehistoric and early medieval periods, when the great raised bogs of counties Longford, Westmeath, and Offaly were not the empty wastelands they can appear today, but crossed by routes connecting communities, grazing grounds, and resources that the bog itself provided. The anaerobic, acidic conditions of the bog have preserved the timber in a way that dry land never could, which is why these roads survive at all.