as the road enters/exits Dublin city centre The route starts (east-west) at
Aston Quay in central Dublin. It then runs to
Palmerstown where it becomes the
N4. It starts again in
Lucan, at the same grade-separated interchange at which the M4 begins. Less than 1 km west it crosses the
River Liffey into
Leixlip in
County Kildare. It then passes through Leixlip,
Maynooth,
Kilcock,
Enfield, and
Clonard before rejoining the N4 west of
Kinnegad. The official description of the R148 from the
Roads Act 1993 (Classification of Regional Roads) Order 2012 reads: :
R148: Dublin — Kinnegad, County Westmeath (Part of old National Route 4) :Between its junction with R138 at OConnell Bridge in the city of Dublin and its junction with M50 at Palmerstown Upper in the county of South Dublin via Astons Quay, Crampton Quay, Wellington Quay, Essex Quay, Wood Quay, Merchants Quay, Ushers Quay, Ushers Island, Victoria Quay (and via Frank Sherwin Bridge, Wolfe Tone Quay, Sarsfield Quay, Ellis Quay, Arran Quay, Inns Quay, Ormond Quay Upper, Ormond Quay Lower, and Bachelors Walk), Kingsbridge, Saint Johns Road West, Con Colbert Road and Chapelizod Bypass in the city of Dublin: and Redcowfarm in the county of South Dublin :::and :between its junction with N4 at Cooldrinagh in the county of South Dublin and its junction with M4 at Heathstown in the county of Westmeath via Leixlip Road in the county of South Dublin: Leixlip Bridge at the boundary between the county of South Dublin and the county of Kildare: Main Street in the town of Leixlip; Collinstown, Blakestown; Dublin Road, Main Street and Mill Street in the town of Maynooth; Maws; Harbour Street, Bridge Street (and via New Lane, The Square and New Road) and Church Street at Kilcock; Allen Bridge and Boycestown in the county of Kildare: Harris’s Bridge at the boundary between the county of Kildare and the county of Meath: Johnstown, Innfield Relief Road, Newcastle and Kilmurry in the county of Meath: Blackwater Bridge at the boundary between the county of Meath and the county of Kildare: Ballynadrumny in the county of Kildare: Leinster Bridge at the boundary between the county of Kildare and the county of Meath: Clonard, Ardnamullen, Hardwood and Rossan in the county of Meath: Kinnegad Bridge at the boundary between the County of Meath and the County of Westmeath: Main Street at Kinnegad; and Correllstown in the county of Westmeath. ==See also==