The Southern Way Link Road ( Welsh : Ffordd Gyswllt y Ffordd Deheuol ) , generally known simply as Southern Way , was built in two parts ; the first section of Southern Way to be completed was between Newport Road ( A4161 road ) and the Eastern Avenue ( A48 road ) in 1978 . The final section of the link road was built between Newport Road and the Rover Way – Lamby Way roundabout and was opened in 1984 at a cost of £ 9 million and include the East Moors Viaduct , which is also known as the Southern Way Flyover . In 1987 it was envisaged that the present single @-@ carriage would be " twinned " as a dual @-@ carriageway , the same as the rest of the PDR . The 2 @.@ 25 km ( 1 @.@ 40 mi ) link road now run from the Rover Way – Lamby Way Roundabout ( 51 @.@ 493127 ° N 3 @.@ 133759 ° W ﻿ / 51 @.@ 493127 ; -3.133759 ﻿ ( Rover Way – Lamby Way Roundabout ) ) to the Llanedeyrn Interchange ( 51 @.@ 507202 ° N 3 @.@ 145853 ° W ﻿ / 51 @.@ 507202 ; -3.145853 ﻿ ( Llanedeyrn Interchange ) ) on the A48 .