Designed and mainly operated as a coal mining freight railway, its creation and demise was wholly defined by the South Wales Coalfield.
Passenger traffic was neither heavy nor a major contribution to line finances, and so in 1900 the GWR introduced steam rail motors.
The last passenger train ran on 13 June 1964 as a result of the Beeching cuts, leaving only the freight service to Maerdy Colliery.
The line was placed into maintenance only upkeep from June 1986 and subsequently closed completely in August that year, after the coal mined at Maerdy was raised at Tower Colliery.
In 2004, Rhondda Cynon Taff council came to an arrange with Network Rail to buy the trackbed from just north of Maerdy Junction to Margaret Street, Pontygwaith and convert it into a relief road for Ynyshir.