The official description of the R131 from the Roads Act 1993 (Classification of Regional Roads) Order 2012[1] reads:
R131: Drumcondra Road - East Link Bridge - Merrion Gates, Dublin
Between its junction with R132 at Drumcondra Road and its junction with R118 at Merrion Road via Clonliffe Road, Poplar Row, East Wall Road, East Link Toll Bridge, Toll Bridge Road, Sean Moore Road, Beach Road and Strand Road all in the city of Dublin.