|Location Map ( geo)|
|From:||Kylemore Road, Chapelizod (W) (O097347)|
|To:||Frank Sherwin Bridge, Dublin (O139344)|
|Distance:||4.4 km (2.7 miles)|
|Meets:||R112, R111, R101, R148|
|Former Number(s):||N4 T3|
The R109 forms a historic route into Dublin from the west.
It begins at a junction with the R112 Kylemore Road to the west of the Dublin suburb of Chapelizod. After running south-eastward along Lucan Road for some 570 m, the route swings left and then right, crossing the Anna Livia Bridge in Chapelizod to reach the north side of the Liffey. From here it continues eastwards along Chapelizod Road and Conyngham Road, with Phoenix Park to the north and the river to the south.
Soon after meeting the R111 – coming in from the right in the district of Islandbridge – the route terminates opposite Dublin Heuston railway station at a junction with the R148 at the northern end of the Frank Sherwin Bridge.
In the original 1920s numbering scheme, the R109 was the T3, a designation which shows what an important route it was. At its east end it continued to O'Connell Bridge, while west of Chapelizod the T3 continued all the way to Sligo.
While the straight Conyngham Road was a reasonable route for motoring, the bridge at Chapelizod was a bottleneck and this became a major problem as national traffic increased and Dublin suburban development spread into areas beyond Chapelizod.
In 1977, the T3 became the N4. In 1987 the issue at Chapelizod was resolved with a bypass, which moved the road to the south of Heuston Station. This meant what's now the R109 became entirely redundant as part of the strategic road network, but it is still used locally.