The bridge carrying the Herbertstown to Limerick road over this quietly westward-flowing river is a skewed structure, meaning its arches do not meet the water at a right angle but cross it on the diagonal. This is a relatively demanding engineering solution, requiring the stonework of the arch's underside to follow a twisted formation rather than a simple curve. The result, set in level Co. Limerick pasture, is a piece of considered construction that most drivers cross without a second thought.

The present three-arched bridge replaced an earlier one on the same spot, recorded in Samuel Lewis's 1837 Topographical Dictionary of Ireland as an ancient structure of nine arches. No trace of that older crossing survives. The replacement is built of roughly coursed limestone blocks, with cut limestone voussoirs, the wedge-shaped stones that form an arch, featuring chamfered edges and fine line dressing. The keystones are slightly longer than the rest. Pointed cutwaters on the upstream, eastern side of the piers are tiered, helping to divide the current. The base of the central pier is of mass concrete, visible during low water. On the northern side of the river, the parapet wall extends as a causeway some 168 metres over wet ground, rising to a maximum external height of 3.3 metres on its western face. Small rectangular drainage outlets are cut at intervals along the base of this wall to carry water away from the road surface.

The bridge sits on the R514 and is readily accessible, with the river here forming the townland boundary between Caherelly West to the north and Ballingooley and Rawlesytown to the south. It appears as Longford Bridge on the Ordnance Survey six-inch map. The causeway parapet to the north is the most rewarding thing to examine closely; the springing walls at either end of the arches are built of large, well-cut limestone blocks with punch dressing and fine tooling around the edges, a level of finish that suggests some care was taken with the original construction. The southern arch and its pier are dry, and vegetation obscures the northern pier, so the clearest view of the structure's detail is from the downstream, western side.