The R112 road is a regional road in south Dublin, Ireland. It begins at the junction with the R148 road at Chapelizod and arcs southeastwards, then eastwards across the middle of south Dublin, ending at the Mount Merrion junction of the R138. The road is a single carriageway, with cycle lanes on some stretches. Improvements to the road have been made over the last 10 years, the most significant being at Dundrum Cross where the road was widened to make room for the new Luas bridge and Dundrum bypass (R117 road). The R112 is 15.2 kilometres (9.4 mi) long (map of the road).