A togher, as such bog roads are known in Ireland, was the practical answer to the problem of crossing wet, unstable ground; builders would lay timbers across the soft surface to create a firm trackway, much as a modern worker might lay boards across mud. What makes the Rathgarrett example quietly arresting is how much of its construction logic remains legible: the careful arrangement of closely placed transverse timbers supported by longitudinal runners at either end and beneath the centre, the whole thing orientated on a northeast to southwest axis and traceable for at least 26 metres.

When a single cutting was excavated under licence in 2014, the structural details confirmed what the surface survey had suggested. The trackway, between 2.4 and 4.1 metres wide, was built from roundwood, split roundwood, and heavier timbers, the species being alder and birch throughout. A scatter of brushwood had been worked in among the longitudinal runners as additional support. Twenty-seven worked ends were recorded on the timbers, shaped to chisel or wedge points with flat facets, the marks of Iron Age carpentry applied with evident care to what was, essentially, a utilitarian crossing. Accelerator mass spectrometry dating of a birch fragment placed the construction somewhere between 183 and 46 BC, situating the togher firmly in the Irish Iron Age. The timbers themselves were in poor condition by the time they were examined, most fractured along their length, and the sphagnum peat that would once have sealed and preserved the structure had largely gone, a consequence of the bog's industrial history.