R101

North Circular Road in Phibsborough.

The R101 is the number allocated to Dublin's North Circular Road ("Circular Road North"), so called because it once formed the northern boundary of the city. The vast majority of it is also part of the Dublin Outer Orbital Route, and it does an important job getting traffic around the outskirts of the city. It provided a very important link to the port prior to the tunnel being built.

While the majority of the road is straight-forward, the start is a little convoluted, as it threads its way around Phoenix Park on Infirmary Road. The tunnel planned in the 1960s was never built. It then makes its way through Phibsborough, past the prison and hospital at Mountjoy, and down to Summerhill.

Beyond here the road turns slightly industrial, as it enters North Wall and passes under Connolly Station, and then turns into the former Docklands area. A large viaduct carries the road over the former railway yard, but this is now masked by the flats built there instead. Most of the Docklands buildings have been replaced by new-build apartments, but the North Wall Freight Depot maintains an industrious tone. The road ends on the R131 outside the Point Shopping Centre.

Until 2012, short sections through Phibsborough were part of the N2 and N3.

The General Traffic Plan (1965) called for North Circular Road to be made "free of crossings". In places, a one way system was proposed around the canal. Later in the 1960s a motorway was proposed along the canal, rendering the North Circular Road upgrade redundant. The motorway would have met the R101 at a large interchange near Spencer Dock.