|Location Map ( geo)|
|To:||Dún Laoghaire (O240288)|
|Distance:||7.1 km (4.4 miles)|
|Meets:||M50, N11, R118, R113, R119|
|Route outline (key)|
It runs along the seafront at Dun Laoghaire, on a route which was built in the 1930s to relieve what is now known as the R119. It moves onto a 1980s bypass of Blackrock, and then runs straight up the leafy Mount Merrion Avenue, where it takes a break to kick off the N11.
The N31 re-emerges to carry the N11's through traffic, joining the well-aligned Brewery Road. It passes under the new Luas flyover, before taking a final run up the large dual carriageway to Sandyford.