A togher is a wooden trackway laid across wet or marshy ground, allowing people and livestock to cross terrain that would otherwise be impassable. They range from simple arrangements of brushwood to sophisticated constructions of split oak planks, and they survive precisely because the anaerobic conditions of a bog prevent the timber from decaying in the way it would above ground. The Derryad example is classified as a class 3 togher, a designation that places it within a broader typological framework used to describe the construction method and complexity of these ancient roads.

This particular togher was noted during a field survey carried out in 1988, recorded through the personal communication of B. Raftery, one of Ireland's foremost authorities on bog roads and wetland archaeology. The survey work formed part of a broader effort to catalogue the remarkable concentration of ancient trackways preserved in the Irish midlands, where extensive boglands have acted as accidental archives of prehistoric and early historic movement and infrastructure. Longford, sitting at the edge of the great midland raised bogs, contains numerous such features, most of them invisible to the casual eye and known only through specialist survey.