The official description of the R323 from the Roads Act 1993 (Classification of Regional Roads) Order 2006[1] reads:
R323 Kiltimagh - Knock - Ballyhaunis, County Mayo
Between its junction with R320 at Main Street Kiltimagh and its junction with N60 at Hazelhill in the town of Ballyhaunis via Thomas Street at Kiltimagh; Roosky, Cloonlee, Knock, Greenwood, Tooraree; and Relief Road in the town of Ballyhaunis all in the county of Mayo.
The road in southeast County Mayo is 20 km (12 mi) long (map of the road).